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Effects of response habits on the performance of obese, average and fluctuator subjects Aves, Penelope Jill 1976

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EFFECTS OF RESPONSE HABITS ON THE PERFORMANCE OF OBESE, AVERAGE AND FLUCTUATOR SUBJECTS by PENELOPE J I L L AVES B.A., N o r t h e r n I l l i n o i s U n i v e r s i t y , 1970 M.S., Purdue U n i v e r s i t y , 1972  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY  in THE FACULTY OF GRADUATE STUDIES Department o f P s y c h o l o g y  We a c c e p t t h i s t h e s i s as conforming to the required  standard  THE UNIVERSITY OF BRITISH COLUMBIA JULY, 1976 Penelope J i l l Aves, 1976  In  presenting  this  an a d v a n c e d d e g r e e the I  Library  further  for  shall  agree  thesis  in  at  University  the  make  that  it  partial  freely  permission  his  of  this  written  representatives. thesis  for  financial  of  University  of  British  gain  Columbia  ^ \ \1Q, C  of  Columbia,  British for  extensive by  the  understood  \" SVCtKjU>k>Y  2075 W e s b r o o k P l a c e Vancouver, Canada V6T 1W5  Date  is  permission.  Department  The  for  It  of  available  s c h o l a r l y p u r p o s e s may be g r a n t e d  by  fulfilment  shall  requirements  reference copying of  Head o f  that  not  the  I  agree  and this  be a l l o w e d  that  study. thesis  my D e p a r t m e n t  copying or  for  or  publication  w i t h o u t my  ABSTRACT  The purpose o f t h i s study was  t o a s s e s s the r e l a t i v e i n f l u e n c e o f  s t i m u l u s cues and response t e n d e n c i e s on the b e h a v i o r o f average c o n s i s t e n t l y o r i n c o n s i s t e n t l y overweight undergraduate v o l u n t e e r s who to  one of t h r e e weight  individuals.  groups on the b a s i s of weight h i s t o r y , p r e s e n t The t h r e e groups  c o n s i s t e n t l y average, c o n s i s t e n t l y overweight, and  the  included  "fluctuator"  T h i s l a s t group c o n s i s t e d of s u b j e c t s whose weights  past two y e a r s had v a r i e d between the average and  classifications. All  female  p a r t i c i p a t e d i n the study were a s s i g n e d  weight, and t r i c e p s s k i n f o l d measurements.  subjects.  The  the  over  overweight  There were 20 s u b j e c t s i n each o f the t h r e e groups.  s u b j e c t s completed two e x p e r i m e n t a l t a s k s and were a l s o  a d m i n i s t e r e d the Eysenck P e r s o n a l i t y I n v e n t o r y ( E P I ) , Form A. first  and  The  e x p e r i m e n t a l t a s k , used p r e v i o u s l y by S i k e s , i n v o l v e d g u e s s i n g  colors  ( b l a c k or red) o f 120 c o n s e c u t i v e l y p r e s e n t e d c a r d s .  S e v e n t y - f i v e p e r cent o f the f i r s t  90 c a r d s i n the s e r i e s were b l a c k ,  w h i l e a l l o f the remaining 30 c a r d s were r e d . no performance  As expected, t h e r e were  d i f f e r e n c e s between groups on the f i r s t  however, on the l a s t  90 c a r d s ;  30 cards c o n s i s t e n t l y overweight p a r t i c i p a n t s made  s i g n i f i c a n t l y more e r r o r s than e i t h e r average or f l u c t u a t o r T h i s f i n d i n g i s c o n s i s t e n t w i t h Singh's  subjects.  deficit-in-response-inhibition  h y p o t h e s i s which m a i n t a i n s t h a t overweight p e o p l e have g r e a t e r difficulty of  i n changing e s t a b l i s h e d response t e n d e n c i e s than do p e o p l e  average weight.  I t i s noteworthy,  study o n l y p e o p l e who  however, t h a t i n t h e p r e s e n t  had been c o n s i s t e n t l y overweight f o r the p a s t  iii  two  y e a r s e x p e r i e n c e d more d i f f i c u l t y  i n changing t h e i r  established  responses. The  second e x p e r i m e n t a l t a s k i n v o l v e d l e a r n i n g two  a s s o c i a t e word l i s t s  i n an A-B/A-Br t r a n s f e r paradigm.  paired As  expected,  t h e r e were no performance d i f f e r e n c e s between groups on t h e list.  Contrary  to expectations,  however, t h e r e were a l s o no  ences between groups on the t r a n s f e r l i s t of p r e v i o u s l y e s t a b l i s h e d responses. t e n t l y overweight s u b j e c t s response-inhibition The  d i d not  initial differ-  which r e q u i r e d t h e  suppressio  Thus, i n t h i s s i t u a t i o n c o n s i s -  show the p r e d i c t e d  deficit-in-  effect.  r e s u l t s , then, o f f e r p a r t i a l support f o r Singh's i n t e r p r e t a -  t i o n of o b e s i t y i n terms of d i f f e r e n t i a l response t e n d e n c i e s .  No  support i s found f o r S c h a c h t e r ' s i n t e r p r e t a t i o n which s t r e s s e s  the  e f f e c t s of e x t e r n a l cues, s i n c e obese s u b j e c t s t h a t was  s u p e r i o r to t h a t of average s u b j e c t s  Results  from a n a l y s e s  t h a t t h e r e were no  of s u b j e c t s ' s c o r e s  d i d not a t any  show performance  point.  on the EPI  indicated  d i f f e r e n c e s between the t h r e e weight groups  e i t h e r e x t r a v e r s i o n or  on  neuroticism.  In a d d i t i o n t o p r o v i d i n g  some support f o r Singh's h y p o t h e s i s ,  the  e x p e r i m e n t a l f i n d i n g s i n t h i s study i n d i c a t e t h a t  i t i s important  consider  weight when i n v e s -  r e c e n t weight h i s t o r y as w e l l as present  tigating behavioral  d i f f e r e n c e s between overweight and  uals.  of t h i s r e s e a r c h  Implications  i n d i v i d u a l s were  discussed.  f o r treatment of  normal  to  individ-  overweight  iv  TABLE OF CONTENTS Page ABSTRACT  ii  L I S T OF TABLES  vi  L I S T OF FIGURES  vii  ACKNOWLEDGEMENT  viii  CHAPTER 1 :  INTRODUCTION  1  Experimental Findings S u b c l a s s i f i c a t i o n s of O b e s i t y R a t i o n a l e of the P r e s e n t I n v e s t i g a t i o n Overview of Experiment CHAPTER 2 :  2 7 11 13  METHOD  17  Subjects P e r s o n a l i t y Measures P h y s i c a l Measures Materials Procedure  17 19 19 19 21  CHAPTER 3 :  RESULTS  Subject Groupings E x p e c t a n c y Change T a s k Paired Associate Learning Eysenck P e r s o n a l i t y Inventory C o r r e l a t i o n s between Degree of Measures Weight H i s t o r y CHAPTER 4 :  24 24 24 26 30 O b e s i t y and  DISCUSSION  E x p e c t a n c y Change Paired Associates E x t r a v e r s i o n and N e u r o t i c i s m General Discussion I m p l i c a t i o n s f o r Treatment Future Directions  Experimental 39 42 46 46 48 49 51 53 55  REFERENCES  57  APPENDICES  .61  Appendix A: Appendix B:  I n i t i a l Weight Q u e s t i o n n a i r e E x p e r i m e n t a l C o n s e n t Form  61 62  Page Appendix C: Appendix D: Appendix E: Appendix F: Appendix G:  I n i t i a l and Transfer L i s t s used i n Paired Associate Task Instructions for the F i r s t L i s t of the Paired Associate Task Instructions f o r the Transfer L i s t of the Paired Associate Task Weight History and Medical Information Questionnaire Summary of Results Mailed to Experimental Participants  63 64 65 66 68  vi  LIST OF TABLES Page T a b l e I.  Table I I .  Table I I I .  T a b l e IV.  T a b l e V.  Table VI.  Table VII.  Table VIII.  T a b l e IX.  T a b l e X.  Table XI.  Table XII.  Table XIII.  Means and standard d e v i a t i o n s o f s u b j e c t c h a r a c t e r i s t i c s by weight c l a s s i f i c a t i o n s  20  Means and standard d e v i a t i o n s o f expectancy change measures by weight c l a s s i f i c a t i o n  25  Means and standard d e v i a t i o n s o f p a i r e d a s s o c i a t e l e a r n i n g measures by weight classifications  29  Means and standard d e v i a t i o n s o f e x t r a v e r s i o n , n e u r o t i c i s m , and l i e s c a l e s c o r e s  31  Means arid standard d e v i a t i o n s o f expectancy change measures f o r i n t r o v e r t s and e x t r a v e r t s  33  Means and standard d e v i a t i o n s o f p a i r e d a s s o c i a t e l e a r n i n g measures f o r i n t r o v e r t s and e x t r a v e r t s  34  Means and s t a n d a r d d e v i a t i o n s o f expectancy change measures f o r normals and n e u r o t i c s  36  Means and s t a n d a r d d e v i a t i o n s o f p a i r e d a s s o c i a t e l e a r n i n g measures f o r normals and n e u r o t i c s  37  Means and standard d e v i a t i o n s o f e x t r a v e r s i o n and n e u r o t i c i s m scores by p e r s o n a l i t y classifications  38  Means and standard d e v i a t i o n s o f expectancy change measures by p e r s o n a l i t y c l a s s i f i c a t i o n s  40  Means and standard d e v i a t i o n s o f p a i r e d a s s o c i a t e l e a r n i n g measures by p e r s o n a l i t y classifications  41  C o r r e l a t i o n s between dependent measures f o r t r a n s f e r - o f - t r a i n i n g t a s k s and t r i c e p s s k i n f o l d by weight c l a s s i f i c a t i o n s  43  A n a l y s e s o f group p r o p o r t i o n s f o r h i s t o r y o f overweight d u r i n g v a r i o u s l i f e p e r i o d s  44  LIST OF FIGURES  Number of errors i n l a s t 30 t r i a l s expectancy change task by weight classification  viii  ACKNOWLEDGEMENT  I would l i k e to express my appreciation to my committee chairman, Dr. Jerry Wiggins, for his advice and encouragement throughout investigation.  this  I also wish to thank Drs. Park Davidson, Boris  Gorzalka, and Nancy Schwartz f o r consenting to serve on my committee and for suggestions concerning my research. Special assistance with the data analysis was provided by V i r g i n i a Green. I would also l i k e to thank Dr. G.J. Johnson for h i s help with paired associate learning procedures.  1  CHAPTER 1 INTRODUCTION  Overweight has become a problem of great concern i n i n d u s t r i a l ized nations where a large proportion of the population i s well-fed but quite sedentary.  Ponderal index values, calculated from height  and weight, were obtained for a s t r a t i f i e d national sample of more than 19,000 Canadians as part of a national n u t r i t i o n survey (Nutrition Canada, 1973).  These figures indicated that more than half of the  adult population (over 20 years of age) i n Canada i s overweight.  In a  1966 survey of a s t r a t i f i e d sample of the population of the United States by the Elmo Roper Company, 42% of the females and 36% of the males sampled f e l t that they were over t h e i r best weight (Dwyer & Mayer, 1970).  Preoccupation with overweight among a large segment of  the population can also be deduced from the number of popular books and a r t i c l e s dealing with diets, the p r o l i f e r a t i o n of low-calorie food products and beverages, and the number of commercial reducing establishments throughout the western world.  Medical s p e c i a l i s t s are i n -  creasingly warning the population of the health hazards of overweight. Even such an established t r a d i t i o n as l a grande cuisine i n France i s feeling the effects of increasing weight-consciousness.  Michel  Guerard, an outstanding French chef, has recently developed a novel approach termed l a cuisine minceur (Wechsberg, 1975).  Derived from  the French word mince, meaning "slim", t h i s revolutionary approach attempts to provide high-quality gastronomic fare prepared with lowc a l o r i e , low-cholesterol ingredients. In view of the concern with overweight from many sources, the  2  p r o l i f e r a t i o n of research on t h i s topic i s not surprising. aimed at producing weight loss i n obese patients have met, recently, with uniformly dismal r e s u l t s .  Programs until  In 1958, the conclusion from  a Cornell Conference on Obesity was that "most obese patients w i l l not remain i n treatment. not  Of those who do remain i n treatment, most w i l l  lose s i g n i f i c a n t poundage, and of those who  w i l l regain i t promptly" (p. 87).  do lose weight, most  With the advent of behavioral tech-  niques of psychotherapy some programs have met with greater success (e.g., Harris, 1969; Stuart, 1967; Wollersheim, 1970).  The main prob-  lems with treatments presently involve obtaining c l i n i c a l l y s i g n i f i c a n t rather than s t a t i s t i c a l l y s i g n i f i c a n t weight losses i n patients and finding methods of maintaining the desired weight once i t has been achieved. Experimental Findings The remarkable recidivism of the overweight has prompted some investigators to look f o r behavioral differences between obese and normal persons i n situations both relevant and irrelevant to eating behavior.  Studies by Schachter and others have shown that the eating behav-  i o r of obese subjects i s more affected by external cues such as taste (Nisbett, 1968), v i s i b i l i t y of food (Johnson, 1974), and time of day (Schachter & Gross, 1968) than the eating behavior of normal subjects. Other investigators have shown that overweight subjects respond more to environmental cues than normal subjects i n situations quite unrelated to eating behavior, e.g., r e c a l l of items viewed on s l i d e s (Rodin, Herman, & Schachter, 1974) and proof-reading with and without d i s t r a c t i o n (Rodin, 1973).  Recently t h i s stimulus-binding theory has been  q u a l i f i e d somewhat i n that obese individuals are assumed to be more  3  responsive than normal subjects to highly salient or potent cues i n the environment while they are less responsive to weak or minimal cues.  P l i n e r (1973), f o r instance, found an interaction between body  weight and cue salience of auditory signals i n a time estimation task. This finding i l l u s t r a t e s the importance of considering the salience of external cues when investigating differences i n environmental responsiveness between overweight and normal subjects. Despite the considerable body of data i n support of the hypothes i s that the obese are especially susceptible to external cues, some researchers are d i s s a t i s f i e d with t h i s explanation for the behavioral differences observed between obese and normal subjects.  Singh (1973)  has proposed a d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n hypothesis to account for the findings and maintains that the behavior of overweight subj e c t s i s mainly controlled by response tendencies.  He states that  "stimulus-bound behavior i n obese subjects would be evident only i n those situations where external cues and response tendencies are compatible.  I f cues and response tendencies are incompatible as exem-  p l i f i e d by negative transfer of t r a i n i n g or reversal-learning s i t u a tions, the behavior of obese subjects would be controlled by existing response tendencies" (p. 221). By constructing experimental s i t u a tions which necessitated changing dominant response patterns, Singh has repeatedly demonstrated among obese subjects.  a d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n effect  In one experiment  (Singh, 1973) obese and  normal subjects received i n i t i a l training that was either compatible or incompatible with the subsequent obtain food.  experimental response required to  When t r a i n i n g was compatible with the experimental  4  response, obese subjects ate s l i g h t l y but not s i g n i f i c a n t l y more food than normal subjects; however, under the incompatible t r a i n i n g condit i o n obese subjects consumed s i g n i f i c a n t l y less food than normals. Singh (1973) also showed that obese subjects performed worse than normals on a time estimation task when previous i n t e r f e r i n g t r a i n i n g was given, and displayed greater problem-solving when a mental set was  created.  of a well-known Schachter  r i g i d i t y than normals  In another experiment along the l i n e s  i n v e s t i g a t i o n , Singh and Sikes (1974)  offered obese and normal subjects chocolates and cashews, both being either wrapped or unwrapped.  Schachter and Friedman (Schachter,  1971)  had provided either shelled or unshelled almonds to subjects and  had  found that obese subjects ate more of the unshelled and less of the shelled almonds than normals who  ate about the same amount of both.  They concluded  that obese subjects were less w i l l i n g to work for food  than normals.  In Singh's study, neither subject weight nor wrapping  had an effect upon chocolate comsumption, but i n the case of cashews the obese subjects ate less of the wrapped than unwrapped nuts while there was no difference for the normals.  In t h i s s i t u a t i o n , past  experience seemed to be the important v a r i a b l e determining willingness to work for food. Sikes (1974) carried out a series of experiments i n which predictions from the stimulus-binding and d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n theories d i f f e r e d .  Results from three of the four experiments were  consistent with the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n hypothesis.  In the  f i r s t experiment, obese subjects were more resistant than normal subjects to an attitude change manipulation of strongly held a t t i t u d e s .  5  The second experiment required participants to predict the colors of black and red cards i n a stack.  Overweight subjects had greater  d i f f i c u l t y than normals i n changing t h e i r expectations when the color feedback went from 75% black to 100% red.  When subjects were required  to perform a well-learned motor task i n a different fashion, obese subjects did worse than normal subjects.  I t was only i n the discrim-  ination reversal experiment that the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n hypothesis was not supported because the obese subjects did not show the expected reversal effect while the normal subjects did. ;  Sikes's  conclusion from these results was that the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n theory i s a better predictor of obese behavior than the stimulusbinding theory across a v a r i e t y of s i t u a t i o n s . E f f o r t s have been made by Singh and h i s associates to eliminate a number of a l t e r n a t i v e hypotheses which might account f o r the behavioral differences found between obese and normal subjects.  Possible factors  which might contribute to behavioral differences include i n t e l l i g e n c e , compliance, self-esteem, and motivation.  Sikes (1974) found no  differences between obese and normal subjects i n i n t e l l e c t u a l a b i l i t y as measured by the vocabulary subtest of the Wechsler Adult gence Scale.  Intelli-  In another experiment, results from measures of s e l f -  exteem, compliance, and motivation indicated there were no differences between obese and normal subjects (Sikes & Singh, 1974).  Thus, i t  appears that no a l t e r n a t i v e explanation has yet been found for the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n effect displayed by obese subjects i n various contexts. The d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n hypothesis provides an explanat i o n for some of the known facts about obese behavior which have  6  presented problems for the stimulus-binding approach.  For example,  i f external cues determine eating behavior, why do the obese stop eating before a l l the food within sight has been consumed?  Schachter  (1971) has stated that the difference between obese and normal eating behavior appears to be due to the size of meals rather than the number of meals.  This observation can be explained by the d e f i c i t - i n -  response- i n h i b i t i o n view since obese subjects are seen as having problems with terminating an ongoing response; thus, they would be expected to continue responding longer than normal subjects, e.g., continuing to eat longer at meals, but not expected to consume a l l food within sight or to eat more meals than normal subjects. It must be pointed out that the predictions derived from the external cues and response i n h i b i t i o n hypotheses are not incompatible in many cases.  Singh (1973) has pointed out that both can account f o r  many of the observed behavioral differences between obese and normal subjects.  Continued  investigation of situations i n which opposite  predictions can be derived from these two viewpoints would seem warranted i n order to specify classes of situations where one or the other might be more applicable. An important  difference between these two l i n e s of research  involves the c l a s s i f i c a t i o n of experimental subjects. his associates generally use the 1959 Metropolitan L i f e  Schachter and Insurance  Company norms for i d e a l weight and c l a s s i f y subjects according to the percentage of deviation from the average weight for a given height. Subjects up to 10% above the average weight are c l a s s i f i e d as normal while those above 15% of the average weight are considered obese.  7  Though students p a r t i c i p a t i n g i n body^eontact sports are eliminated, there are s t i l l problems including differences i n body frame and clothing.  Singh uses the t r i c e p s s k i n f o l d thickness to c l a s s i f y sub-  j e c t s as obese since t h i s measure r e f l e c t s excess fatness rather than weight above average and i s not influenced by body frame or height (Seltzer & Mayer, 1965).  Correlations reported between these two  indices of overweight are somewhat v a r i a b l e :  .52 for females and  .72  for males (Singh, 1973); .81 for males and females (Sikes, 1974). Therefore,  i t would seem that researchers  i n this area should make use  of skinfold measures i n addition to weight deviations to ensure that experimental participants are both consistently and accurately to t h e i r appropriate weight c l a s s i f i c a t i o n s .  assigned  Such a methodological  refinement would also f a c i l i t a t e comparisons of findings from various investigations of obesity. Subclassifications of Obesity One problem with most of the research investigating differences between obese and normal subjects involves the rather a r t i f i c i a l dichotomy employed.  A United States Public Health Services report  (1966) states that "obesity, the result of a p o s i t i v e c a l o r i c balance, can be the outcome of a number of disturbances. causes and subsequent manifestations be considered  the same.  The v a r i a t i o n s i n  indicate that not a l l obesity  can  For this reason, some investigators have come  to use the p l u r a l term 'obesities' rather than obesity" (p. 33). Despite such statements most studies have looked at differences between one obese and one normal group.  The exceptions  to this rule have pro-  vided i n t e r e s t i n g and occasionally c o n f l i c t i n g r e s u l t s .  In a  8  treatment setting involving obese patients with adult onset of the problem, Grinker, Hirsch, and Levin (1973) found l i t t l e adverse react i o n to weight reduction, e.g., anxiety or depression, though previous research with patients having a history of juvenile onset indicated a number of negative reactions to weight l o s s .  In another comparison  of juvenile versus adult onset of obesity, Grinker, Glucksman, Hirsch, & V i s e l t a e r (1973) found that subjects with juvenile onset underestimated time intervals a f t e r weight reduction, but this was not true of adult onset or normal subjects. Sikes (1974) divided her obese subjects into subgroups determined by age of onset (before or a f t e r age 10), evidence of traumatic experience p r i o r to weight gain, and substantial weight loss at some point i n time which was subsequently regained.  No differences, however, were  found between the subgroups on any of the experimental measures. In a study involving obese and normal g i r l s at an Eastern U.S. college, Decke, Gold and Porikos (Schachter & Rodin, 1974) found that t h e i r results depended on the degree of obesity of the subjects.  In an  immediate r e c a l l task, moderately obese g i r l s (16%-48% overweight) did better than normals while the highly obese (53.3%-97.7% overweight) did worse than the normals.  Nisbett (1972) reported that obese sub-  j e c t s who were 40% or more overweight behaved s i m i l a r l y to normal subj e c t s i n terms of amount of good and bad-tasting i c e cream consumed, while obese subjects who were 15%-40% overweight were more responsive to taste and ate more of the good-tasting and less of the bad-tasting ice cream than either the normal or the substantially obese group.  In  another experiment investigating degree of obesity, Rodin (1975) found  9  that moderately obese subjects (15%-40% overweight) were s i g n i f i c a n t l y more influenced by t h e i r taste preferences for milkshakes i n terms of food ingestion and food ratings than were average and obese (60% or more overweight) subjects. Another i n t e r e s t i n g c l a s s i f i c a t i o n of obesity involves the consistency with which one maintains a p a r t i c u l a r weight.  Johnson (1974)  used weight deviations from the 1959 Metropolitan L i f e Insurance tables to c l a s s i f y his subjects as obese versus normal. subjects who  Only those  reported weights over the past two years consistent with  t h e i r present c l a s s i f i c a t i o n were used i n the experiment.  In another  study, Rodin (1975) divided subjects within three weight c l a s s i f i c a tions (average, moderately overweight, obese) on the basis of s t a b i l i t y of weight and eating patterns over the past two years i n order to determine closeness to b i o l o g i c a l set point.^  Subjects were c l a s s i f i e d  as below set point i f their weights had fluctuated by more than 7% i n the past two years and they reported some dietary r e s t r i c t i o n s .  If  t h e i r weights had fluctuated no more than 3% with no dietary r e s t r i c tions and they weighed as much as they ever had, subjects were considered to be at t h e i r set point.  Weight s t a b i l i t y had no s i g n i f i c a n t  effect on either food preference ratings or food intake when minimal e f f o r t was  required; however, when more e f f o r t was  required to obtain  food, subjects below set point were more deterred than those at set  B i o l o g i c a l set point i s a t h e o r e t i c a l notion r e f e r r i n g to an i n d i v i d ual organism's optimal state of adipose tissue mass. The b i o l o g i c a l set point i s a function of the number of adipocytes or f a t c e l l s i n the body, this number being determined by heredity and early n u t r i t i o n a l experience and therefore not subject to change i n adult l i f e (Cabanac, Duclaux, & Spector, 1971; Nisbett, 1972).  10  point.  Though t h e s e r e s u l t s a r e i n t e r e s t i n g i n r e l a t i o n t o the b i o l o g -  i c a l set p o i n t h y p o t h e s i s , the data p r e s e n t e d do not i n d i c a t e whether any o f the s u b j e c t s c l a s s i f i e d as below s e t p o i n t had s u f f i c i e n t  weight  ranges over the past two y e a r s t o span two  clas-  s i f i c a t i o n s used by Rodin.  I f some o f the s u b j e c t s i n the below s e t  p o i n t group had v a r i e d between the weight i n t e r e s t i n g t o know how  or more of the weight  c a t e g o r i e s , i t would be  these s u b j e c t s responded  on the  experimental  measures. Two  s t u d i e s by Schachter and h i s a s s o c i a t e s ( N i s b e t t ,  S c h a c h t e r , 1971) t e n t weight  have a l s o attempted  to look at subjects with  c l a s s i f i c a t i o n s a c c o r d i n g to weight  employed o n l y post hoc a n a l y s e s .  h i s t o r y but  inconsis-  they  In N i s b e t t ' s (1968) experiment  good and b a d - t a s t i n g i c e cream, weight  with  r e c o r d s i n d i c a t e d than 37% o f  the normal s u b j e c t s had been overweight weight  1968;  a t the time o f the experiment.  i n the past but were of normal These " f o r m e r l y f a t " s u b j e c t s  e x h i b i t e d g r e a t e r r e s p o n s i v e n e s s t o t a s t e than the normals w i t h no h i s t o r y o f overweight respect.  and behaved s i m i l a r l y to the obese i n t h i s  N i s b e t t (1972) has more r e c e n t l y a t t r i b u t e d the o b e s e - l i k e  b e h a v i o r o f these p r e v i o u s l y overweight  s u b j e c t s t o the f a c t t h a t  are below the b i o l o g i c a l l y - p r o g r a m m e d p r e f e r r e d weight behave l i k e the obese, i . e . , as i f they were hungry. and Friedman ( S c h a c h t e r , 1971) those normals who  they  or s e t p o i n t and In the  Schachter  study w i t h s h e l l e d and u n s h e l l e d almonds,  had been overweight  behaved as the obese d i d , e a t i n g  the s h e l l e d but not the u n s h e l l e d n u t s . One  i n v e s t i g a t i o n has produced  the " f o r m e r l y f a t " behaving  r e s u l t s contrary to t h i s n o t i o n of  l i k e the obese ( P r i c e & G r i n k e r , 1973).  11  Obese s u b j e c t s  from the o b e s i t y  research  program at  Rockefeller  U n i v e r s i t y H o s p i t a l were c l a s s i f i e d on the b a s i s of degree of and  age  of onset  subjects preload  ( j u v e n i l e , adolescent,  and  ate more than normal v o l u n t e e r s and  cracker-tasting conditions  adult).  obesity  These obese  from the community i n both  and were more r e s p o n s i v e to  t h e i r t a s t e p r e f e r e n c e s than normals.  No  d i f f e r e n c e s were found  between the obese subgroups as a f u n c t i o n of degree of o b e s i t y of onset i n terms of amount eaten or r e s p o n s i v e n e s s to t a s t e ences.  W i t h i n the normal group, 43%  p r i o r h i s t o r y of overweight.  The  of the  subjects  "formerly  or  Rationale  taste  reported  some  f a t " i n t h i s study behaved the  preferences.  o f the P r e s e n t  Investigation  In view of the above r e s u l t s , r e s e a r c h or s u b j e c t s whose recent  investigating "fluctuators",  weight h i s t o r y and  present status  some degree of v a c i l l a t i o n between obese and an independent group might shed some l i g h t t o r y r e s u l t s of p r e v i o u s s t u d i e s . varying  age  prefer-  as the normals w i t h no h i s t o r y of overweight both i n terms of amount eaten and  the  indicate  normal c l a s s i f i c a t i o n s ,  on the  seemingly  as  contradic-  I n d i v i d u a l s w i t h h i s t o r i e s of w i d e l y  body weights c o n s t i t u t e a group w e l l - w o r t h i n v e s t i g a t i n g f o r a  number o f f u r t h e r r e a s o n s .  As  the North American p o p u l a t i o n  stated e a r l i e r , a large proportion seems to be  p r o b a b l y f o r b o t h a e s t h e t i c and  concerned w i t h i t s weight  m e d i c a l reasons.  The  mass media p r e s e n -  t a t i o n s of i d e a l p h y s i c a l specimens are i n v a r i a b l y s l i m . consultants  are i n c r e a s i n g l y f o c u s i n g  u t i n g f a c t o r i n heart visibility  of the  disease  and  of  Medical  on overweight as a major c o n t r i b -  o t h e r p h y s i c a l problems.  The  high  d i e t i n d u s t r y i n d i c a t e s t h a t a s u b s t a n t i a l number of  12  people are attempting to do something about their weight.  A 1966  survey i n the United States indicated that only 54% of the men and 30% of the women sampled ate whatever they wanted with no concern over gaining weight  (Dwyer & Mayer, 1970).  Within t h i s same group, 6% of  the males and 14% of the females sampled said they were presently on a diet while an additional 7% of the men they dieted from time to time. American goes on 1.25 being 60-90 days.  and 13% of the women said that  Wyden (1965) stated that the average  diets a year with the average length of these  The popularity of diets varies with the time of year,  the most common being post-Christmas season and p r i o r to summer. These facts create a picture of a substantial portion of society engaging i n a continual b a t t l e with overweight, i . e . , losing by dieting and/or exercising, regaining, and beginning again.  The seriousness of  t h i s problem i n terms of medical consequences i s indicated by a U.S. Public Health Service report (1966) which states: Serum cholesterol levels are elevated during periods of weight gain, thus increasing the r i s k of deposition. There i s no evidence to show that once cholesterol i s deposited i t can be removed by weight reduction. It i s possible that a patient whose weight has fluctuated up and down a number of times has been subjected to more atherogenic stress than a patient with stable though excessive weight (p. 71). Stuart and Davis (1972) have expressed concern with these observations and stated that weight reduction programs should be aimed at obtaining a stable weight which can be maintained over time. The prevalence of on-and-off dieting within North American society indicates that investigations which include a group of fluctuators along with obese and normal groups might provide interesting results i n terms of hypotheses previously advanced about overweight  individuals  13  and contribute some information which could be incorporated into therapeutic procedures aimed at producing weight loss i n various types of individuals.  Since the negative t r a n s f e r - o f - t r a i n i n g tasks u t i l i z e d by  Singh i n h i s research provide a test of the predictions of both the external cue and response i n h i b i t i o n hypotheses,  the u t i l i z a t i o n of t h i s  type of task with normal, obese, and "fluctuator" subjects could provide data on the merits of these two hypotheses using a more d i f f e r e n t i a t e d c l a s s i f i c a t i o n of obesity.  Also, tasks of this sort have not been  employed with obese subgroups d i f f e r i n g i n weight s t a b i l i t y to determine whether d i f f e r e n t i a l responses might be obtained i n these situations. Overview of Experiment Obese, normal, and fluctuator subjects were asked to perform t r a n s f e r - o f - t r a i n i n g tasks.  two  To allow a comparison of results between  the present study and previous research based on the deficit-in-responsei n h i b i t i o n hypothesis, the black and red card color expectancy designed by Pervin (1960) and i n i t i a l l y  task  employed with obese subjects by  Sikes (1974) was used i n the present investigation.  This task measures  the extent to which subjects are able to modify t h e i r expectations according to the feedback they receive.  Subjects were asked to guess  the colors of 120 consecutive cards i n a stack with participants viewing each card a f t e r every guess. the l a s t 30 were a l l red.  The f i r s t 90 cards were 75% black, while  On the basis of previous research i t was  hypothesized that obese subjects would have more d i f f i c u l t y i n changing t h e i r i n i t i a l expectations than normal subjects.  It was also hypothe-  sized that fluctuator subjects, would have less d i f f i c u l t y i n making the change than the consistently obese, but more d i f f i c u l t y than the  14  consistently average participants. The second t r a n s f e r - o f - t r a i n i n g task involved paired associate learning.  Subjects were trained to a s p e c i f i e d c r i t e r i o n on an  l i s t and then asked to learn a second l i s t .  initial  The second l i s t was made  up of the same words as the o r i g i n a l l i s t , but the response words had been randomly assigned to d i f f e r e n t stimulus words thus creating an interference e f f e c t from the previous ing  training.  Paired associate learn-  tasks have not been used previously with overweight and normal  subjects though the paradigm involved i n paired associate learning of a negative  transfer l i s t would seem to be an i d e a l s i t u a t i o n for comparing  the predictions of the stimulus-binding tion theories.  and d e f i c i t - i n - r e s p o n s e - i n h i b i -  If overweight subjects are more responsive  to external  cues than normal subjects, the obese participants should perform better on both l i s t s of the paired associates task than the normal subjects. If, on the other hand, the d i f f e r e n t i a l performance of overweight and normal subjects i s due to response tendencies as Singh (1973) has proposed, then the obese and normal subjects should d i f f e r mainly i n performance on the second or transfer l i s t because performance on t h i s l i s t would require suppressing words.  established responses to the  Results of the majority of investigations involving negative  t r a n s f e r - o f - t r a i n i n g situations have provided in-response-inhibition theory. i t was  stimulus  support for the d e f i c i t -  On the basis of t h i s body of research  hypothesized that consistently overweight subjects would perform  more poorly than consistently average subjects on the second l i s t i n the paired associate learning task.  It was  also hypothesized that  fluctuating subjects or those with highly variable weight h i s t o r i e s  15  would perform b e t t e r than the obese s u b j e c t s worse than the average  on the second l i s t  subjects.  There i s a p o t e n t i a l a l t e r n a t i v e e x p l a n a t i o n d i c t e d d i f f e r e n c e s between obese, normal, and the p a i r e d a s s o c i a t e s l e a r n i n g t a s k . 1976)  has  but  a v a i l a b l e f o r the  f l u c t u a t o r subjects  A recent  review (M.W.  summarized the f i n d i n g s of numerous e x p e r i m e n t a l i n v e s t i g a -  v e r s i o n and  neuroticism  memory t a s k s .  1971;  on  Eysenck,  t i o n s on the r e l a t i o n s h i p between the p e r s o n a l i t y dimensions of  and  pre-  and  performance on a v a r i e t y of v e r b a l  A number of s t u d i e s  Howarth, 1969)  A recent  Eysenck  a l o n g e r p e r i o d f o r responding than i s convenNo  d i f f e r e n c e s were found i n  terms of c o r r e c t responses between groups v a r y i n g neuroticism,  r e l a t e d t o response l a t e n c y .  but  along  the  dimensions  i n d i v i d u a l d i f f e r e n c e s were  Eysenck concluded from t h e s e f i n d i n g s  t h a t e x t r a v e r t s are not b e t t e r l e a r n e r s but of i n f o r m a t i o n  rather faster r e t r i e v e r s  than i n t r o v e r t s .  R e g a r d l e s s of the s p e c i f i c e x p l a n a t i o n performance between e x t r a v e r t s and tasks with b r i e f periods  f o r the d i f f e r e n c e s i n  i n t r o v e r t s on p a i r e d  associate  a l l o w e d f o r r e s p o n d i n g , i t would seem appro-  p r i a t e to i n c l u d e a measure of e x t r a v e r s i o n w i t h i n the p r e s e n t t i g a t i o n to determine whether obese, normal, and d i f f e r along  extra-  lists  i n v e s t i g a t i o n by M.W.  t i o n a l l y used i n p a i r e d a s s o c i a t e t a s k s .  of e x t r a v e r s i o n and  Bone,  l e a r n i n g performance of  v e r t s i s s u p e r i o r to t h a t of i n t r o v e r t s on p a i r e d a s s o c i a t e  (1975) a l l o w e d s u b j e c t s  learning  ( A l l s o p p & Eysenck, 1974;  have shown t h a t the  which are h i g h l y c o m p e t i t i v e .  extra-  t h i s dimension.  Results  from one  fluctuator  study  inves-  subjects  (Taylor,  1971)  i n d i c a t e d a s i g n i f i c a n t c o r r e l a t i o n between the i n t r o v e r s i o n f a c t o r and  s m a l l amount of l e a n body mass i n b l a c k , male,  college-age  16  students. was  The  Eysenck P e r s o n a l i t y Inventory  administered  provides  to a l l s u b j e c t s i n t h i s  (Eysenck & Eysenck,  investigation.  s c o r e s on b o t h the n e u r o t i c i s m and  inventory  e x t r a v e r s i o n dimensions as  w e l l as a l i e s c a l e to c o n t r o l f o r the response set of desirability.  This  1968)  social  17  CHAPTER 2 METHOD  Subjects Volunteer psychology,  s u b j e c t s were o b t a i n e d from 42 undergraduate c l a s s e s  e d u c a t i o n , and n u t r i t i o n .  Female students who  e s t e d i n p a r t i c i p a t i n g i n an experiment c o n c e r n i n g the between body b u i l d , b e h a v i o r ,  and p e r s o n a l i t y  were i n t e r -  relationship  were asked  to complete an  i n i t i a l q u e s t i o n n a i r e (Appendix A) on weight h i s t o r y over the past years.  Potential volunteers indicated  t h e i r h i g h e s t and  lowest  over the p a s t two y e a r s as w e l l as t h e i r p r e s e n t w e i g h t s . history  i n f o r m a t i o n was  consistently  used to s e l e c t s u b j e c t s i n i t i a l l y  normal, o r c o n s i s t e n t l y  of Canadian h e i g h t s and weights (Pett experimental  The as  & O g i l v i e , 1956).  weight  During  t r i c e p s s k i n f o l d measures classifi-  1970)  h i s t o r y data i n d i c a t e d of the t a b l e d  skin-  s i x t i e t h c e n t i l e s of a s t a n d a r d  d i s t r i b u t i o n of s k i n f o l d measures f o r females & Welfare,  table  the  P a r t i c i p a n t s were c l a s s i f i e d as normal i f t h e i r t r i c e p s  f o l d measures were between the t e n t h and  Education,  weights  fluctuators,  were taken, and these f i g u r e s were used f o r the f i n a l s u b j e c t cations.  two  obese a c c o r d i n g to a s t a n d a r d  appointment, h e i g h t , weight, and  in  (U.S.  Dept. of H e a l t h ,  and a l s o t h e i r p r e s e n t weight and weight  a c o n s i s t e n t l y normal c l a s s i f i c a t i o n  average weight f o r a g i v e n h e i g h t  (Pett  (within  & Ogilvie,  10%  1956)).  S u b j e c t s were c l a s s i f i e d as obese i f t h e i r t r i c e p s s k i n f o l d measures were above the e i g h t i e t h c e n t i l e of a standard measures f o r females data i n d i c a t e d  d i s t r i b u t i o n of s k i n f o l d  and a l s o t h e i r p r e s e n t weights and weight  a consistently  obese c l a s s i f i c a t i o n  history  (15% o r more above  18  the t a b l e d average weight f o r a g i v e n h e i g h t ) .  P a r t i c i p a n t s were  c l a s s i f i e d as f l u c t u a t o r s i f t h e i r weights over the p a s t two y e a r s had v a r i e d s u b s t a n t i a l l y enough t h a t t h e i r h i g h e s t weights were a t l e a s t 15% above t h e i r lowest weights and t h e i r lowest weights were w i t h i n the normal c l a s s i f i c a t i o n w h i l e t h e i r h i g h e s t weights were w i t h i n t h e obese c l a s s i f i c a t i o n .  No r e s t r i c t i o n s were p l a c e d on the s k i n f o l d  measure f o r the f l u c t u a t o r  group.  2  To ensure t h a t s u b j e c t groups were homogeneous w i t h r e s p e c t t o o t h e r p o t e n t i a l l y important v a r i a b l e s , two g e n e r a l r e s t r i c t i o n s were p l a c e d upon p a r t i c i p a t i o n i n the experiment.  Only p o t e n t i a l  volunteers  between 18-25 y e a r s of age were c o n t a c t e d f o r p a r t i c i p a t i o n i n the study.  Secondly, s u b j e c t s whose f l u c t u a t i o n s i n weight were a r e s u l t  of pregnancy, l a c t a t i o n , o r s e r i o u s i l l n e s s were not i n c l u d e d i n the study.  T h i s i n f o r m a t i o n was o b t a i n e d from the i n i t i a l  questionnaire  and t h e e x p e r i m e n t a l consent form (Appendix B ) . S i x t y s u b j e c t s p a r t i c i p a t e d i n the experiment.  Twenty s u b j e c t s  were o b t a i n e d from t h e sample o f p o t e n t i a l v o l u n t e e r s who agreed t o p a r t i c i p a t e i n the experiment and who met t h e requirements o f the c o n s i s t e n t l y overweight c l a s s i f i c a t i o n .  To m a i n t a i n e q u a l numbers o f  s u b j e c t s i n the t h r e e weight groups, twenty s u b j e c t s were a l s o o b t a i n e d f o r b o t h the f l u c t u a t o r and normal groups.  Descriptive  2 The f l u c t u a t o r group i n c l u d e d b o t h i n d i v i d u a l s who were overweight and i n d i v i d u a l s who were w i t h i n the normal weight range a t the time of the experiment. Weight and s k i n f o l d measurements taken on s u b j e c t s w i t h i n the f l u c t u a t o r group i n d i c a t e d that n i n e s u b j e c t s were obese and s i x s u b j e c t s were normal a t the time o f the e x p e r i ment w h i l e f i v e o f the s u b j e c t s d i d not f i t e i t h e r c l a s s i f i c a t i o n as t h e i r weights and/or s k i n f o l d measurements were above t h e normal range but below the obese range used i n the experiment.  19  s t a t i s t i c s on age,  h e i g h t , weight, and  t h r e e groups a r e shown i n T a b l e  t r i c e p s s k i n f o l d f o r these  I.  P e r s o n a l i t y Measures The cipants.  Eysenck P e r s o n a l i t y Inventory was T h i s 57-item s e l f - r e p o r t  administered  i n v e n t o r y p r o v i d e s s c o r e s on e x t r a -  v e r s i o n and n e u r o t i c i s m as w e l l as a l i e s c a l e . t o r y was to  used becuase t h i s v e r s i o n c o n t a i n s no  e a t i n g h a b i t s or food  to a l l p a r t i -  Form A of the items  inven-  d i r e c t l y relevant  preferences.  P h y s i c a l Measures T r i c e p s s k i n f o l d measurements were o b t a i n e d w i t h a Lange S k i n f o l d Caliper.  S u b j e c t s were weighed on a p o r t a b l e household s c a l e which  had been a d j u s t e d w i t h r e f e r e n c e t o a s t a n d a r d m e d i c a l b a l a n c e s c a l e . Height  measurements were o b t a i n e d on a w a l l c h a r t .  A l l s u b j e c t s were  weighed and measured i n indoor c l o t h i n g and without  shoes.  Materials One  hundred and twenty standard p l a y i n g c a r d s , not  c a r d s , were used f o r the expectancy change t a s k . were randomly p r e s e n t e d  but  red  30 cards were a l l r e d .  c a r d s , and  the l a s t  The  i n c l u d i n g face  first  lists  of 12 p a i r s of  s y l l a b l e a d j e c t i v e s were c o n s t r u c t e d w i t h a d j e c t i v e s taken  groups to l e a r n one each s u b j e c t was A-B,  A-Br  25%  twofrom Melton  S u b j e c t s were randomly a s s i g n e d w i t h i n  of the two  initial  c o n s t r u c t e d from items  t r a n s f e r paradigm.  s t i m u l i and  cards  c o n s i s t e d i n t o t a l of 75% b l a c k and  For the p a i r e d a s s o c i a t e t a s k two  (1940) .and Haagen (1949).  90  To  lists.  The  second l i s t  i n her i n i t i a l  list  c o n s t r u c t the second l i s t s ,  responses from the i n i t i a l  lists  for  using a the  were randomly r e - p a i r e d .  Table I Means and Standard Deviations of Subject Characteristics by Weight C l a s s i f i c a t i o n s 3  Weight (pounds)  Percent Overweight  Triceps Skinfold (mm.)  Height (inches)  Age  Average (n=20)  130.90 (11.28)  -.59 (3.23)  13.75 (2.24)  64.85 (2.78)  19.95 (1.85)  Fluctuator (n=20)  151.40 (20.61)  16.34 (15.05)  21.55 (5.19)  64.50 (2.61)  19.75 (1.65)  Obese (n=20)  170.55 (28.38)  29.60 (16.80)  28.10 (2.79)  64.78 (2.84)  19.80 (1.88)  a  Standard deviations i n parentheses  21  Items were s e l e c t e d t o minimize t h e e f f e c t s o f s t r u c t u r a l and meaningf u l s i m i l a r i t y both w i t h i n and a c r o s s t h e l i s t s .  The l i s t s were p r e -  sented on a memory drum a t a 2:2 r a t e w i t h f o u r seconds between  trials.  To minimize s e r i a l l e a r n i n g e f f e c t s , f o u r d i f f e r e n t random o r d e r s o f the 12 p a i r s i n each l i s t be found i n Appendix  were used.  I n i t i a l and t r a n s f e r l i s t s may  C.  Procedure S u b j e c t s were chosen on the b a s i s o f i n i t i a l q u e s t i o n n a i r e d a t a and c o n t a c t e d by telephone t o arrange e x p e r i m e n t a l appointments. of t h e s u b j e c t s c o n t a c t e d no l o n g e r wished keep t h e i r appointments.  Four  to p a r t i c i p a t e or f a i l e d to  Upon a r r i v a l at t h e l a b o r a t o r y  were asked t o s i g n an e x p e r i m e n t a l consent form.  participants  Then each s u b j e c t  p a r t i c i p a t e d i n the two t a s k s i n v o l v i n g t h e r e v e r s a l o f e s t a b l i s h e d response t e n d e n c i e s and completed (EPI).  t h e Eysenck P e r s o n a l i t y I n v e n t o r y  The o r d e r o f t h e two t r a n s f e r t a s k s was c o u n t e r b a l a n c e d w i t h i n  each s u b j e c t c l a s s i f i c a t i o n . t a s k she was asked t o complete  When a s u b j e c t had f i n i s h e d t h e f i r s t the EPI.  Following the completion of  t h i s s c a l e t h e second t a s k was a d m i n i s t e r e d . One  o f the t a s k s i n v o l v e d changing e x p e c t a n c i e s o f c a r d  which was p r e v i o u s l y used by S i k e s (1974).  colors  The procedure and i n s t r u c -  t i o n s g i v e n here a r e i d e n t i c a l t o those used i n h e r experiment.  The  s u b j e c t and experimenter were s e a t e d a t a t a b l e w i t h a s t a c k o f p l a y i n g cards between them.  The experimenter s a i d , " I have here a s t a c k o f  c a r d s , which I w i l l t u r n over one a t a time.  B e f o r e I t u r n over each  c a r d , I would l i k e f o r you t o guess whether i t w i l l be r e d o r b l a c k . What c o l o r do you t h i n k the f i r s t  c a r d w i l l b e ? " The s u b j e c t made a  22  guess, and the experimenter turned the card over to show her the correct color.  The experimenter then put the card on the table,  recorded her response, and asked, "What color do you think this card w i l l be?" This procedure was followed f o r a l l 120 cards.  As stated  e a r l i e r the f i r s t 90 cards were 75% black and 25% red while the l a s t 30 cards were a l l red. . When the color proportion changed no i n d i c a t i o n was given to the subject that this had occurred. The second task involved learning two l i s t s of paired associates. The subject was seated i n front of a memory drum with the experimenter seated behind her coding the subject's responses. given f o r the f i r s t l i s t began.  Instructions were  (Appendix D) and t r a i n i n g on the f i r s t  list  Each subject was given a maximum of 25 a n t i c i p a t i o n t r i a l s on  the f i r s t l i s t .  Training on the f i r s t l i s t ended when the subject  achieved two perfect r e c i t a t i o n s of the f i r s t l i s t or when she had received 26 presentations of the l i s t , whichever occurred After a rest i n t e r v a l of approximately  first.  two minutes the subject was  given the instructions f o r the transfer l i s t  (Appendix E).  Then the  subject was given ten a n t i c i p a t i o n t r i a l s (not including the f i r s t presentation) on the transfer l i s t . After each subject had completed her second t r a n s f e r - o f - t r a i n i n g task, she was asked to f i l l out a f i n a l questionnaire containing items r e l a t i n g to weight h i s t o r y , diet r e s t r i c t i o n s , and medical which might be relevant to weight (Appendix F).  information  F i n a l l y , weight,  height, and triceps skinfold measurements were taken on each subject. At the end of the experiment, subjects were given a b r i e f explanation of the experimental  hypotheses and procedures;  a fuller  statement, which included the results and conclusions of the experi ment was mailed to subjects at t h e i r home addresses at a l a t e r date approximately four months a f t e r they had participated  (Appendix G).  CHAPTER 3 RESULTS Subject Groupings There were s i g n i f i c a n t d i f f e r e n c e s between the t h r e e weight groups on t h e weight (F(2,57)=17.38, p<.01), p e r c e n t overweight p<v01) and t r i c e p s s k i n f o l d  (_F(2,57)=77 .97,  CF(2,57)=26.46,  p<.01) measures.  Compari-  sons between a l l p a i r s of means of the t h r e e groups on these measures were made u s i n g the Tukey " a " procedure  (Winer, 1962,  c o n t r a s t s between mean p a i r s were s i g n i f i c a n t (weight, percent overweight,  p. 87).  f o r the t h r e e measures  and t r i c e p s s k i n f o l d ) at the  .05  Subject groups d i d not d i f f e r s i g n i f i c a n t l y on e i t h e r h e i g h t age  (_F< 1) .  (Chapter  (F< 1) or  The means and standard d e v i a t i o n s a r e shown i n T a b l e I  Change Task  S u b j e c t s i n the t h r e e weight c l a s s i f i c a t i o n groups were compared on the number of i n c o r r e c t responses 90 t r i a l s 25%  level.  2).  Expectancy  and  All  of the expectancy  red.  initially  they made i n the  change t a s k when the cards were 75%  first black  A one-way a n a l y s i s of v a r i a n c e i n d i c a t e d t h a t t h e r e were  no s i g n i f i c a n t d i f f e r e n c e s between average,  f l u c t u a t o r , and obese sub-  j e c t s i n terms of the number of e r r o r s made i n the f i r s t (F(2,57)< 1).  The means and  the expectancy  change t a s k a r e shown i n T a b l e I I .  cards  s t a n d a r d d e v i a t i o n s on the measures used i n  The numbers of i n c o r r e c t responses weight groups on t r i a l s  90  made by s u b j e c t s i n the t h r e e  76-90 were a l s o compared to determine whether  t h e r e were any d i f f e r e n c e s between groups immediately change i n the c a r d r a t i o i n the s t a c k from 75%  p r i o r to the  b l a c k and 25%  red to a l l  Table I I Means and Standard Deviations by Weight  Errors T r i a l s 1-90  3  of Expectancy Change Measures  Classification  Errors T r i a l s 76-90  Errors T r i a l s 91-120  Average (n=20)  39.05 (6.36)  5.90 (1.71)  4.05 (2.28)  Fluctuator (n=20)  38.50 (4.05)  6.65 (1.18)  4.05 (1.57)  Obese (n=20)  39.05 (4.30)  6.25 (1.62)  5.85 (2.87)  a  Standard deviations i n parentheses  26  red.  Results  indicated that  t h e r e were no s i g n i f i c a n t d i f f e r e n c e s  between t h e average, f l u c t u a t o r , and obese groups i n terms o f t h e number  o f e r r o r s made i n t r i a l s  76-90 (F(2,57)=1.22,  The number o f e r r o r s made by s u b j e c t s on t r i a l s the  n.s.).  i n t h e t h r e e weight groups  91-120 when a l l t h e cards were r e d was t h e c r i t i c a l measure on  expectancy change t a s k .  i n d i c a t e d that  Results  from a one-way a n a l y s i s of v a r i a n c e  t h e r e was a s i g n i f i c a n t d i f f e r e n c e between groups on t h e  number o f e r r o r s made i n t r i a l s  91-120 (F_(2,57)=4.07, p<.05).  To i n v e s -  t i g a t e t h e s o u r c e o f t h i s d i f f e r e n c e comparisons were made between t h e group means u s i n g  the Tukey " a " procedure (Winer, 1962, p. 8 7 ) . The  number o f e r r o r s made by t h e obese group was s i g n i f i c a n t l y g r e a t e r  than  the number of e r r o r s made by both t h e f l u c t u a t o r and the average groups (p<.05).  The f l u c t u a t o r group d i d n o t d i f f e r s i g n i f i c a n t l y from the  average group on number of e r r o r s i n c a r d s 91-120. The number o f e r r o r s made by t h e t h r e e weight groups on t h e l a s t 30 cards wass:-. a l s o a n a l y s e d i n b l o c k s o f t e n t r i a l s t o i n v e s t i g a t e the p o s s i b i l i t y o f a d i f f e r e n t i a l d i s t r i b u t i o n o f e r r o r s between the groups over t r i a l s . variance  Results  from a 3 X 3 between-within a n a l y s i s o f  i n d i c a t e d s i g n i f i c a n t e f f e c t s b o t h f o r weight group  (F(2,57)=4.07, p<.05) and t r i a l s  (F2,114)=106.15, p<.01), but the i n t e r -  a c t i o n between weight groups and t r i a l s was not s i g n i f i c a n t (_F(4,114)=1.23, n . s . ) . made by s u b j e c t s  Figure  1 i l l u s t r a t e s t h e t o t a l number o f e r r o r s  i n t h e t h r e e weight groups on t h e l a s t  30 t r i a l s by  b l o c k s of t e n t r i a l s . Paired Associate  Learning  S u b j e c t s i n t h e t h r e e weight groups were compared  on two measures  27  Figure 1.  Number of errors i n Last 30 T r i a l s of Expectancy Change Task by Weight C l a s s i f i c a t i o n  28  of f i r s t  list  l e a r n i n g t o determine whether t h e groups d i f f e r e d i n  performance on t h e p a i r e d Results  associate  t a s k without response  interference.  from an a n a l y s i s o f t h e number o f t r i a l s n e c e s s a r y f o r  achieving  the learning  c r i t e r i o n f o r the f i r s t  list  indicated  there  were no s i g n i f i c a n t  d i f f e r e n c e s between t h e t h r e e weight groups on  t r i a l s to c r i t e r i o n  (F_ <1) .  subjects  within  each o f t h e t h r e e weight groups who d i d not a c h i e v e two  consecutive perfect pation  trials.  There was an a p p r o x i m a t e l y equal number o f  r e c i t a t i o n s of t h e l i s t  i n the a l l o t t e d  T r i a l s c o r e s o f 26 were a s s i g n e d t o those  25 a n t i c i subjects  (6 average, 5 f l u c t u a t o r s , and 5 obese) who had not a c h i e v e d t h e l e a r n ing c r i t e r i o n f o r the f i r s t The but  number o f i n t r a l i s t  list. intrusions  (responses c o n t a i n e d i n the l i s t  g i v e n t o t h e wrong s t i m u l u ) g i v e n by s u b j e c t s  groups on t h e f i r s t  l i s t were a l s o compared.  i n the t h r e e weight  No s i g n i f i c a n t  was  found between groups on t h e number of i n t r a l i s t  The  means and s t a n d a r d d e v i a t i o n s  the p a i r e d ^ a s s o c i a t e  intrusions  f o r a l l o f t h e dependent measures on  on t h e second or t r a n s f e r l i s t  where response  c o m p e t i t i o n was h i g h were compared a c r o s s the t h r e e weight t i o n groups f o r the f i r s t  t r i a l and f o r a l l t e n t r i a l s .  There were a l s o no s i g n i f i c a n t  between groups on e i t h e r the number o f i n t r a l i s t the number o f i n t e r l i s t  intrusions  There was no  differences  intrusions  (F_< 1) o r  (responses which were c o r r e c t on t h e  l i s t ) made i n T r i a l 1 o f the t r a n s f e r l i s t Results  classifica-  d i f f e r e n c e between groups on the t o t a l number o f e r r o r s  made i n T r i a l 1 ( F < 1 ) .  first  (F < 1) .  l e a r n i n g t a s k a r e shown i n T a b l e I I I .  Measures o f l e a r n i n g  significant  difference  (F_<1).  from an a n a l y s i s o f the t o t a l number o f e r r o r s made by  Table III Means and Standard Deviations  3  of Paired Associate Learning Measures  by Weight C l a s s i f i c a t i o n s  First List  Transfer L i s t Trial 1  T r i a l s to Criterion  Intralist Intrusions  Total Errors  Intralist Intrusions  T r i a l s 1-10 Interlist Intrusions  Total Errors  Intralist Intrusions  Interlist Intrusions  Average (n=20)  18.90 (6.58)  21.90 (20.08)  9.95 (1.54)  1.15 (1.46)  .25 (.55)  60.60 (22.87)  12.55 (9.22)  6.10 (5.08)  Fluctuator (n=20)  17.65 (7.94)  21.20 (22.78)  9.20 (2.31)  1.35 (1.31)  .40 (.60)  62.45 (24.97)  12.75 (10.00)  8.35 (5.31)  Obese (n=20)  19.30 (4.77)  19.95 (21.57)  9.55 (1.67)  1.20 (1.24)  .45 (.60)  64.00 (24.91)  12.80 (12.45)  7.15 (3.88)  Standard deviations i n parentheses  30  subjects list  i n t h e t h r e e weight groups on a l l 10 t r i a l s of the t r a n s f e r  i n d i c a t e d t h a t t h e r e were no s i g n i f i c a n t group d i f f e r e n c e s on t h e  t o t a l number of e r r o r s  (F<1).  There were a l s o no s i g n i f i c a n t  ences between groups on e i t h e r the number of i n t r a l i s t (F<1)  or the number of i n t e r l i s t  Eysenck P e r s o n a l i t y Subjects'  intrusions  i n t r u s i o n s (F_(2,57)=1.10,  over a l l 10 t r i a l s of t h e t r a n s f e r  differ-  n.s.) made  list.  Inventory  scores  on the e x t r a v e r s i o n and n e u r o t i c i s m  EPI were compared a c r o s s  t h e t h r e e weight groups.  s c a l e s o f the  There was no  signif-  i c a n t d i f f e r e n c e between groups on the e x t r a v e r s i o n measure (F(2,57)=1.50,  n.s.).  There was  groups on t h e n e u r o t i c i s m Results  a l s o no s i g n i f i c a n t d i f f e r e n c e between  measure (F < 1) .  from an a n a l y s i s of s c o r e s  i n d i c a t e d t h e r e was t h i s measure ( F < 1 ) .  on the l i e s c a l e o f the EPI  no s i g n i f i c a n t d i f f e r e n c e between the groups on T a b l e IV shows the means and standard  of e x t r a v e r s i o n , n e u r o t i c i s m ,  and l i e s c a l e s c o r e s  f o r the  deviations three  weight groups. The r e l a t i o n s h i p o f e x t r a v e r s i o n and n e u r o t i c i s m on the two e x p e r i m e n t a l tasks was classifications. scale  t o performance  i n v e s t i g a t e d i n d e p e n d e n t l y of weight  High and l o w - s c o r i n g  subjects  on the  extraversion  (upper and lower 27% of the d i s t r i b u t i o n of e x t r a v e r s i o n  were compared on each of t h e dependent measures f o r t h e two t a l tasks. scorers  The mean s c o r e s  on the e x t r a v e r s i o n  scores)  experimen-  s c a l e f o r h i g h and  ( e x t r a v e r t s and i n t r o v e r t s ) were, r e s p e c t i v e l y , 17.00  On t h e expectancy change t a s k , t h e r e were no s i g n i f i c a n t  and  low 8.44.  differences  between e x t r a v e r t s and i n t r o v e r t s on the number o f e r r o r s made i n t h e  31  Table IV Means and Standard Deviations Neuroticism,  3  of Extraversion,  and L i e Scale Scores  Extraversion  Neuroticism  Lie  Average (n=20)  12.45 (3.12)  11.10 (5.26)  2.35 (1.23)  Fluctuator (n=20)  11.95 (3.75)  12.15 (4.13)  2.45 (1.47)  Obese (n=20)  13.85 (3.87)  11.35 (3.44)  2.85 (2.25)  a  Standard deviations i n parentheses  32  first  90 t r i a l s  trials last  (_F(1,30)=1.05, n . s . ) , t h e number of e r r o r s made i n  76-90 (F(1,30)=1.31, n . s . ) , o r t h e number o f e r r o r s made i n t h e  30 t r i a l s  (F<1).  The means and standard d e v i a t i o n s  the expectancy change t a s k f o r i n t r o v e r t s and e x t r a v e r t s  of scores  on  are l i s t e d  i n T a b l e V. On t h e f i r s t  list  of the p a i r e d a s s o c i a t e  t a s k there were no  s i g n i f i c a n t d i f f e r e n c e s between i n t r o v e r t s and e x t r a v e r t s the number o f t r i a l s intrusions  (F<1).  paired associate  The means and standard d e v i a t i o n s  of scores  on t h e  On the f i r s t  t r i a l of the t r a n s f e r l i s t  t h e r e were  s i g n i f i c a n t d i f f e r e n c e s between t h e groups on t h e t o t a l number o f  errors  ( F < 1 ) , the number o f i n t r a l i s t  number o f i n t e r l i s t transfer l i s t and  (F_<1) o r the number of i n t r a l i s t  l e a r n i n g measures f o r i n t r o v e r t s and e x t r a v e r t s a r e  shown i n T a b l e V I . no  to c r i t e r i o n  on e i t h e r  extraverts  intralist  i n t r u s i o n s (jF <1).  intrusions  (_F<1), o r the  For a l l ten t r i a l s of the  t h e r e were no s i g n i f i c a n t d i f f e r e n c e s between i n t r o v e r t s on t h e t o t a l number o f e r r o r s  (F_<1), t h e number of  i n t r u s i o n s ( F < 1 ) , o r the number of i n t e r l i s t  intrusions  (F <1) made i n t r i a l s 1-10. High and l o w - s c o r i n g  subjects  on t h e n e u r o t i c i s m  lower 27% of t h e d i s t r i b u t i o n o f n e u r o t i c i s m  scale  (upper and  s c o r e s ) were a l s o compared  on each o f t h e dependent measures f o r t h e two e x p e r i m e n t a l t a s k s . mean s c o r e s  on t h e n e u r o t i c i s m  scale f o r high  The  and low s c o r e r s  ( n e u r o t i c s and normals) were, r e s p e c t i v e l y , 17.00 and 6.38.  On t h e  expectancy change t a s k t h e r e were no s i g n i f i c a n t d i f f e r e n c e s between neurotics trials  and normals on t h e number o f e r r o r s made i n t h e f i r s t  ( F < 1 ) , t h e number o f e r r o r s made i n t r i a l s  90  76-90 (J_<1), o r  33  Table V Means and Standard D e v i a t i o n s  o f Expectancy  Change Measures  f o r I n t r o v e r t s and E x t r a v e r t s  Errors T r i a l s 1-90  Errors T r i a l s 76-90  Errors T r i a l s 91-120  Introverts (n=16)  37.50 (5.40)  6.44 (1.90)  5.06 (2.77)  Extraverts (n=16)  39.44 (5.30)  5.75 (1.48)  4.88 (2.31)  Standard d e v i a t i o n s  i n parentheses  Table VI Means and Standard Deviations  3  of Paired Associate Learning Measures  for Introverts and Extraverts  First List  Transfer  List  Trial 1 T r i a l s to Criterion  Intralist Intrusions  Total Errors  Intralist Intrusions  T r i a l s 1-10 Interlist Intrusions  Total Errors  Intralist Intrusions  Interlist Intrusions  Introverts (n=16)  17.81 (7.93)  19.75 (16.38)  9.44 (2.25)  .88 (1.36)  .38 (.62)  58.19 (27.67)  10.31 (9.69)  6.69 (4.22)  Extraverts (n=16)  18.88 (6.39)  20.13 (24.44)  9.44 (2.03)  1.06 (1.12)  .31 (.60)  63.13 (23.96)  9.81 (7.06)  6.31 (4.09)  a  Standard deviations i n parentheses  35  the number o f e r r o r s made i n t h e l a s t The  means and standard  30 t r i a l s  d e v i a t i o n s of scores  t a s k f o r normals and n e u r o t i c s a r e l i s t e d On t h e f i r s t  list  (F(l,30)=2.60, n . s . ) .  on t h e expectancy change  i n Table V I I .  of the p a i r e d a s s o c i a t e l e a r n i n g task  there  were no s i g n i f i c a n t d i f f e r e n c e s between groups on e i t h e r t h e number o f t r i a l s to c r i t e r i o n intrusions fell  (F(l,30)=4.09, p=.052) though t h e l a t t e r d i f f e r e n c e j u s t  s h o r t o f t h e c o n v e n t i o n a l l y accepted  means and standard ing  (F(l,30)=1.40, n.s.) o r t h e number o f i n t r a l i s t  l e v e l of s i g n i f i c a n c e .  d e v i a t i o n s o f s c o r e s on t h e p a i r e d a s s o c i a t e l e a r n -  t a s k f o r normals and n e u r o t i c s a r e shown i n T a b l e V I I I .  first  trial  The  of the t r a n s f e r l i s t  t h e r e were no s i g n i f i c a n t  On t h e differences  between normals and n e u r o t i c s on t h e t o t a l number o f e r r o r s (F <1) , the number o f i n t r a l i s t intrusions list  i n t r u s i o n s (F <1), o r t h e number o f i n t e r l i s t  (F(l,30)=1.36, n . s . ) .  t h e r e were no s i g n i f i c a n t  For a l l ten t r i a l s of the t r a n s f e r  d i f f e r e n c e s between groups on t h e t o t a l  number o f e r r o r s (F <1), t h e number o f i n t r a l i s t  intrusions  (F(l,30)=2.07, n . s . ) , o r t h e number o f i n t e r l i s t  i n t r u s i o n s (F <1) .  S u b j e c t s were a l s o d i v i d e d i n t o groups on the b a s i s of t h e i r s c o r e s on both the e x t r a v e r s i o n and the n e u r o t i c i s m groups o f s u b j e c t s  scales.  Four  ( n e u r o t i c - i n t r o v e r t s , n e u r o t i c - e x t r a v e r t s , normal-  i n t r o v e r t s , normal-extraverts)  were formed by c o n s t r u c t i n g a s c a t t e r  p l o t o f t h e b i v a r i a t e d i s t r i b u t i o n o f e x t r a v e r s i o n and n e u r o t i c i s m and  l o c a t i n g c l u s t e r s of subjects  off  scores  t h a t best  falling  i n t h e f o u r quadrants.  e q u a l i z e d t h e number o f s u b j e c t s  Cut-  i n the four  groups were determined and used t o form the f o u r p e r s o n a l i t y groups. Table  IX l i s t s  the means and standard  d e v i a t i o n s o f s c o r e s on t h e  Table VII  Means and Standard D e v i a t i o n s of Expectancy Change Measures 3  for Normals and Neurotics  Errors T r i a l s 1-90  Normals  38.75 (3.61)  Neurotics  39.50 (4.35)  Errors T r i a l s 76-90  Errors T r i a l s 91-120  5.94  4.19  (1.24)  (2.29)  6.38  5.56  (1.50)  (2.53)  Standard deviations i n parentheses  Table VIII Means and Standard Deviations of Paired Associate Learning Measures 3  for Normals and Neurotics  First List  Transfer L i s t Trial 1  T r i a l s to Criterion  T r i a l s 1-10  Intralist Intrusions  Total Errors  Intralist Intrusions  Interlist Intrusions  Total Errors  Intralist Intrusions  Interlist Intrusions  Normals (n=16)  20.25 (6.34)  30.13 (29.28)  9.75 (1.98)  1.06 (1.18)  .38 (.50)  65.06 (28.07)  16.50 (13.71)  6.50 (4.05)  Neurotics (n=16)  17.75 (5.60)  14.06 (12.29)  9.63 (1.71)  .88 (1.45)  .19 (.40)  60.38 (20.09)  10.50 (9.51)  7.19 (5.46)  a  Standard  deviations i n parentheses  T a b l e IX Means and Standard D e v i a t i o n s Neuroticism  3  o f E x t r a v e r s i o n and  Scores by P e r s o n a l i t y  Classifications  Extraversion  Neuroticism  Normal-Introverts (n=13)  9.23 (2.98)  7.69 (2.98)  Normal-Extraverts (n=19)  15.47 (2.06)  8.74 (2.07)  Neurotic-Introverts (n=16)  10.38 (1.93)  15.88 (3.07)  Neurotic-Extraverts (n=12)  15.42 (2.31)  14.33 (1.50)  Standard d e v i a t i o n s i n parentheses  39  extraversion The  and  neuroticism  s c a l e s f o r these f o u r  f o u r p e r s o n a l i t y groups were compared on a l l of the  t a l measures f o r the t h e r e were no  two  learning tasks.  significant  On  number of e r r o r s made i n t r i a l s made i n the l a s t dard d e v i a t i o n s  30 t r i a l s of s c o r e s  were no  first  list  significant  intrusions  f o r the list  to c r i t e r i o n  of s c o r e s  (F<1).  means and  l e a r n i n g task  significant  (F <1)  stanfour  there  T a b l e XI shows the means  the  first  learning  t r i a l of the  d i f f e r e n c e s between the f o u r  (F(3,56)=1.50, n . s . ) ,  on  or the number of  on the p a i r e d a s s o c i a t e On  the  errors  d i f f e r e n c e s between the p e r s o n a l i t y groups  groups on the t o t a l number of e r r o r s intrusions  (F <1),  X.  of the p a i r e d a s s o c i a t e  f o u r p e r s o n a l i t y groups.  t h e r e were no  90 t r i a l s  The  task  personality  on the expectancy change t a s k f o r the  (F(3,56)=1.89, n . s . ) .  standard deviations  four  or the number of  (F(3,56)=1.07, n . s . ) .  e i t h e r the number o f t r i a l s list  first  76-90 CF <1),  p e r s o n a l i t y groups are l i s t e d i n T a b l e the  experimen-  the expectancy change  d i f f e r e n c e s between the  groups on the number of e r r o r s made i n the  On  groups.  (F_ <1) , the number of  or the number of i n t e r l i s t  For a l l t e n t r i a l s of the t r a n s f e r l i s t  intraand  task  transfer personality intralist intrusions  t h e r e were no  signif-  i c a n t d i f f e r e n c e s between groups on the t o t a l number of e r r o r s  (F<1),  the number of i n t r a l i s t intrusions  intrusions  ( F < 1 ) , or the number of  interlist  (_F(3,56)=1.13, n . s . ) .  C o r r e l a t i o n s between Degree of O b e s i t y and Because the  E x p e r i m e n t a l Measures  f l u c t u a t o r group i n c l u d e d both overweight and  weight i n d i v i d u a l s based on measurements taken at the time o f experiment, t h e r e might be  some q u e s t i o n  average the  whether p r e s e n t weight  40  Table X, Means and Standard Deviations  3  of Expectancy Change Measures  by Personality  Errors T r i a l s 1-90  NormalIntroverts (n=13)  37.62  NormalExtraverts (n=19)  38.90  NeuroticIntroverts (n=16)  38.94  NeuroticExtraverts (n=12)  40.09  a  (5.09)  (4.84)  (5.47)  (4.42)  Classification  Errors T r i a l s 76-90  Errors T r i a l s 91-120  6.24  4.46  (1.69)  (2.50)  6.22  4.21  (1.51)  (2.55)  6.57  5.56  (1.36)  (2.73)  6.00  4.33  (1.71)  (1.44)  Standard deviations i n parentheses  T a b l e XI Means and Standard D e v i a t i o n s o f P a i r e d A s s o c i a t e L e a r n i n g Measures by P e r s o n a l i t y C l a s s i f i c a t i o n s 3  First  List  Transfer  List  Trial 1  T r i a l s to Criterion  Trials  1-10  Intralist Intrusions  Total Errors  Intralist Intrusions  Interlist Intrusions  Total Errors  Intralist Intrusions  Interlist Intrusions  NormalIntroverts (n=13)  19.15 (7.02)  29.46 (28.74)  9.61 (2.53)  1.23 (1.30)  .54 (.78)  63.31 (27.19)  15.62 (14.50)  7.38 (5.03)  NormalExtraverts (n=19)  19.74 (6.40)  24.32 (22.54)  9.47 (1.93)  1.68 (1.34)  .42 (.51)  65.37 (24.08)  14.05 (10.11)  8.47 (5.14)  NeuroticIntroverts (n=16)  17.19 (6.88)  17.31 (17.24)  9.56 (1.46)  .75 (1.44)  .25 (.45)  57.13  (22.49)  9.56 (8.41)  7.00 (4.59)  NeuroticExtraverts (n=12)  18.17 (5.88)  11.58 (6.49)  9.67 (1.61)  1.17 (1.03)  .25 (.62)  63.50 (23.65)  11.58 (8.10)  5.25 (4.18)  Standard d e v i a t i o n s i n parentheses  42  c l a s s i f i c a t i o n s were r e l a t e d to the dependent measures r e g a r d l e s s weight h i s t o r y .  To i n v e s t i g a t e  of  t h i s p o s s i b i l i t y , product-moment  c o r r e l a t i o n s were computed between t r i c e p s s k i n f o l d measures o f subj e c t s i n t h e f l u c t u a t o r group and s c o r e s on each of t h e dependent measures f o r t h e two t r a n s f e r - o f - t r a i n i n g t a s k s .  The t r i c e p s s k i n f o l d  measure was used as an i n d i c a t i o n of degree o f o b e s i t y  because o f i t s  r e l a t i v e l a c k of dependence upon body b u i l d and h e i g h t and because t h e t r i c e p s s k i n f o l d measure was h i g h l y  c o r r e l a t e d with percent  a c r o s s a l l s u b j e c t s i n the present i n v e s t i g a t i o n The trials  overweight  (r=.84, p<.001).  number o f e r r o r s made by f l u c t u a t o r s u b j e c t s i n the f i r s t 90  o f t h e expectancy change t a s k was t h e o n l y dependent measure  s i g n i f i c a n t l y r e l a t e d t o t h e magnitude o f the t r i c e p s s k i n f o l d measure (r=-.43, p<.05). and  S i n c e a l a r g e number o f c o r r e l a t i o n s were o b t a i n e d  t h e r e were no s i g n i f i c a n t d i f f e r e n c e s  between t h e t h r e e weight  groups on t h e number o f e r r o r s made i n t h e f i r s t quite possible  that  Correlations  90 t r i a l s  i t is  t h e c o r r e l a t i o n was due t o chance.  were a l s o  computed between t h e t r i c e p s s k i n f o l d  measure and s c o r e s on each of the dependent measures f o r s u b j e c t s i n the  average and obese weight groups.  overweight group t h e degree of o b e s i t y  For s u b j e c t s i n t h e c o n s i s t e n t l y as measured by t h e t r i c e p s  s k i n f o l d was s i g n i f i c a n t l y r e l a t e d t o f i v e o f t h e e x p e r i m e n t a l measures.  The c o r r e l a t i o n s between t h e t r i c e p s s k i n f o l d and s c o r e s on  each o f t h e dependent measures f o r a l l t h r e e weight groups a r e shown i n Table Weight  XII.  History  S u b j e c t s were asked t o i n d i c a t e whether o r not they had been o v e r weight d u r i n g a number of p e r i o d s i n t h e i r l i v e s .  T a b l e X I I I shows  Table XII C o r r e l a t i o n s between Dependent Measures f o r T r a n s f e r - o f - T r a i n i n g Tasks and T r i c e p s  S k i n f o l d by Weight  Classifications  Average  Fluctuator  Obese  -.025 -.048 .198  -.433* -.121 -.075  -.123 -.125  .186 .058  .504* .664**  -.080 -.148 .011  .342 .242 .214  .123 .694** .159  -.158 -.324 -.423*  .151 .256 .229  .422* .376 .363  Expectancy Change Task Errors i n T r i a l s Errors i n T r i a l s Errors i n T r i a l s  1-90 76-90 91-120  .254 .157 .383*  P a i r e d A s s o c i a t e Task First  List  T r i a l s to C r i t e r i o n I n t r a l i s t Intrusions Transfer  List  ( T r i a l 1)  Total Errors I n t r a l i s t Intrusions I n t e r l i s t Intrusions Transfer  List  (Trials  1-10)  Total Errors I n t r a l i s t Intrusions I n t e r l i s t Intrusions  **Significant *Significant  at .01 at .05  level level  Table XIII A n a l y s e s of Group P r o p o r t i o n s f o r H i s t o r y o f Overweight D u r i n g V a r i o u s L i f e  Periods  P r o p o r t i o n Overweight L i f e Periods  Average  Fluctuator  Obese  Significant Multiple Comparisons  Overall X (df = 2)  Average v s . Obese  Childhood  .05  .25  .45  12.465  <.005  Pre-Teens  .05  .40  .60  25.846  <.001  Average v s . F l u c t u a t o r Average v s . Obese  Adolescence  .45  .90  .85  12.507  <.005  Average v s . F l u c t u a t o r Average v s . Obese  Adulthood  .20  .90  1.00  36.190  <.001  Average v s . F l u c t a u t o r Average v s . Obese  Cumulative (at l e a s t once)  .55  1.00  1.00  21.176  <.001  Average v s . F l u c t u a t o r Average v s . Obese  This o v e r a l l ^ i s the test s t a t i s t i c associated with the test of s e v e r a l independent p r o p o r t i o n s (see M a r a s c u i l o , 1966). A l l m u l t i p l e comparisons were conducted w i t h an experimentwise a l p h a l e v e l o f .05.  45  the  p r o p o r t i o n of s u b j e c t s i n each of the t h r e e weight groups  who  i n d i c a t e d t h a t they had been overweight i n v a r i o u s l i f e p e r i o d s and a l s o shows the r e s u l t s from a n a l y s e s performed on t h e s e d a t a .  As can  be seen i n T a b l e X I I I , t h e average group d i f f e r e d from t h e obese in  terms of h i s t o r y of overweight f o r a l l of the l i f e p e r i o d s  group  sampled.  The f l u c t u a t o r group d i f f e r e d from the average group on overweight h i s t o r y f o r a l l l i f e p e r i o d s except t h a t of c h i l d h o o d .  46  CHAPTER 4 DISCUSSION Expectancy Change The  r e s u l t s obtained  consistent with  i n t h e expectancy change t a s k were q u i t e  the p r e d i c t i o n s made c o n c e r n i n g  the behavior  and normal s u b j e c t s from t h e d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n  o f obese theory.  There were no d i f f e r e n c e s between s u b j e c t s i n t h e t h r e e weight groups on t h e f i r s t  p a r t of t h e t a s k which i s c o n s i s t e n t w i t h  Singh's  theory  because s u b j e c t s were not r e q u i r e d t o change a dominant response pattern.  The f a c t t h a t t h e r e were no d i f f e r e n c e s between groups on  the i n i t i a l in  p a r t o f t h e t a s k ; however, i n d i c a t e s t h a t t h e obese s u b j e c t s  t h i s case were n o t more s e n s i t i v e t o t h e e x t e r n a l cues p r o v i d e d by  the c o l o r feedback as would have been expected from t h e s t i m u l u s binding viewpoint.  The s i g n i f i c a n t  d i f f e r e n c e found between groups on  the second p a r t o f t h e t a s k , where s u b j e c t s r e c e i v e d d i f f e r e n t feedback and had t o change t h e i r p r e v i o u s support  expectancies,  f o r t h e d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n theory.  color  provides Group compari-  sons i n d i c a t e d t h a t t h e c o n s i s t e n t l y obese s u b j e c t s made s i g n i f i c a n t l y more e r r o r s i n t h e second phase o f t h e t a s k than both t h e f l u c t u a t o r s u b j e c t s and t h e c o n s i s t e n t l y average s u b j e c t s .  Moreover, most o f t h e  e r r o r s made by s u b j e c t s i n a l l t h r e e weight groups o c c u r r e d first  ten t r i a l s  (see F i g u r e 1, Chapter 3).  s u b j e c t s d i d change t h e i r e x p e c t a n c i e s  during the  T h i s i n d i c a t e s t h a t most  d u r i n g t h e second phase o f the  t a s k , b u t t h e obese s u b j e c t s took l o n g e r t o do so t h a n e i t h e r t h e average o r t h e f l u c t u a t o r s u b j e c t s . The  r e s u l t s from t h e expectancy change t a s k i n t h i s i n v e s t i g a t i o n  47  a r e c o n s i s t e n t w i t h those of S i k e s  (1974).  However, i n her i n v e s t i g a -  t i o n o n l y the obese and normal s u b j e c t s who correct  had made 66%  responses i n the l a s t 15 cards of the i n i t i a l  d i f f e r e d on the second p a r t of the t a s k . performing  p a r t of the  task  T h i s d i f f e r e n c e between h i g h -  obese and normal s u b j e c t s was  t r i a l s a f t e r the c o l o r r a t i o had  or more  s i g n i f i c a n t on the f i r s t  changed.  The  r e s u l t s from the  seven  present  i n v e s t i g a t i o n p r o v i d e a p o t e n t i a l e x p l a n a t i o n f o r the l a c k of an significant experiment.  d i f f e r e n c e between obese and normal s u b j e c t s i n S i k e s ' s In the present  up of s u b j e c t s who years  study  o n l y the obese group which was  made  had been c o n s i s t e n t l y overweight f o r the past  d i s p l a y e d the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n e f f e c t .  two  Though a l l  s u b j e c t s i n the f l u c t u a t o r group were e i t h e r overweight at the time or had  overall  present  been overweight at some p o i n t d u r i n g the past two  years,  these  s u b j e c t s d i d not d i f f e r from the normal s u b j e c t s on the  expec-  tancy  change t a s k .  I t has been suggested t h a t overweight p e o p l e con-  s t i t u t e a heterogeneous group, and  i t i s quite p o s s i b l e that consis-  t e n t l y overweight p e o p l e behave d i f f e r e n t l y from people whose r e c e n t weights have v a r i e d between the average and S i n c e S i k e s d i d not  overweight  d i f f e r e n t i a t e between obese s u b j e c t s on the b a s i s  of r e c e n t weight h i s t o r y , her obese group was geneous than t h a t employed i n the present  deficit-in-response-inhibition effect. groups of obese i n d i v i d u a l s d i f f e r i n g  more h e t e r o -  and might have  d i d not  display a  More r e s e a r c h i n v o l v i n g i n r e c e n t weight h i s t o r y i s  needed to determine whether f l u c t u a t o r and i n other s i t u a t i o n s .  probably  study  i n c l u d e d a number of f l u c t u a t o r s u b j e c t s who  o t h e r t a s k s and  classifications.  obese s u b j e c t s d i f f e r  I t should  on  a l s o be n o t e d t h a t  48  S i k e s ' s sample c o n t a i n e d both males and p a r t i c i p a t e d i n the present  study.  have been r e p o r t e d i n p r e v i o u s female s u b j e c t s (Singh, 1973; sampling  i s probably  females whereas o n l y females  However, s i n c e no  sex d i f f e r e n c e s  i n v e s t i g a t i o n s i n v o l v i n g both male  and  Singh & S i k e s , 1974), t h i s d i f f e r e n c e i n  of minor importance compared t o t h e d i f f e r e n c e i n  c l a s s i f i c a t i o n of obese s u b j e c t s on the b a s i s of weight  history.  S i n c e the f l u c t u a t o r group c o n t a i n e d both obese and normal  indi-  v i d u a l s a c c o r d i n g t o measurements taken at the time of the experiment, t h e r e might be some q u e s t i o n whether present weight  classifications  were r e l a t e d to performance on the second p a r t of the expectancy change t a s k .  The n o n s i g n i f i c a n t c o r r e l a t i o n between the t r i c e p s  f o l d measure and t h a t t h i s was  the number of e r r o r s on the l a s t  not the case.  e n t l y obese (3.77) and  30 cards i n d i c a t e d  A l s o , the mean number of e r r o r s f o r p r e s -  average i n d i v i d u a l s  (4.27) w i t h i n the  group were q u i t e s i m i l a r i m p l y i n g t h a t weight h i s t o r y was f a c t o r i n determining  skin-  the  f l u c t u a t o r s ' responses and not present  fluctuator important classifi-  cations. In summary, the r e s u l t s on the expectancy change t a s k support d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n hypothesis  but i n d i c a t e t h a t o n l y  c o n s i s t e n t l y obese s u b j e c t s have g r e a t e r d i f f i c u l t y e s t a b l i s h e d response on t h i s t a s k .  No  support was  i n changing found  the  the an  f o r the  s e n s i t i v i t y t o e x t e r n a l cues h y p o t h e s i s . Paired Associates On  the second e x p e r i m e n t a l  l e a r n i n g t h e r e were no any  of the e x p e r i m e n t a l  t a s k which i n v o l v e d p a i r e d a s s o c i a t e  d i f f e r e n c e s between the t h r e e weight groups on measures.  T h i s t a s k had been c o n s t r u c t e d as a  49  t e s t of the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n t h e o r y w i t h performance the  second l i s t  on  r e q u i r i n g s u b j e c t s t o suppress responses which had  been e s t a b l i s h e d d u r i n g the l e a r n i n g of the i n i t i a l  list.  Because  no  d i f f e r e n c e s were found between the weight groups on any of the measures of  second l i s t  l e a r n i n g , t h e s e r e s u l t s p r o v i d e no support f o r the view  t h a t obese s u b j e c t s w i l l have g r e a t e r d i f f i c u l t y l i s h e d response t e n d e n c i e s . the  i n overcoming e s t a b -  S i n c e no d i f f e r e n c e s were o b t a i n e d between  weight groups on measures of f i r s t  list  l e a r n i n g , the present  r e s u l t s a l s o do not support t h e s t i m u l u s - b i n d i n g t h e o r y .  I f obese  s u b j e c t s were more r e s p o n s i v e to t h e e x t e r n a l cues i n t h i s t a s k , they should have l e a r n e d the i n i t i a l  list  more q u i c k l y than the average  subj e c t s . The l a c k of any s i g n i f i c a n t  d i f f e r e n c e s between groups and the  extremely l a r g e v a r i a b i l i t y w i t h i n groups on the p a i r e d a s s o c i a t e  task  suggest t h a t o t h e r f a c t o r s a r e more important than weight i n d e t e r m i n ing  performance i n t h i s s i t u a t i o n ,  I t i s p o s s i b l e t h a t some  t i o n o f f a c t o r s i n c l u d i n g memory, i n f o r m a t i o n p r o c e s s i n g ,  combina-  cognitive  s t y l e , and imagery and i n t e l l e c t u a l a b i l i t y determine performance on t a s k s o f t h i s s o r t and t h a t s u b j e c t d i f f e r e n c e s on t h e s e f a c t o r s obscure any d i f f e r e n t i a l performance r e s u l t i n g c a t i o n s or weight h i s t o r y .  from weight  classifi-  R e g a r d l e s s of the e x p l a n a t i o n f o r t h e  l a c k of d i f f e r e n c e s between weight groups on t h i s t a s k , the p r e s e n t f i n d i n g s do not support the p o s i t i o n t h a t obese i n d i v i d u a l s  display  a g e n e r a l i z e d d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n i n comparison t o average individuals, E x t r a v e r s i o n and N e u r o t i c i s m There were no s i g n i f i c a n t  d i f f e r e n c e s between the t h r e e weight  50  groups on t h e p e r s o n a l i t y dimensions of e x t r a v e r s i o n measured by t h e EPI.  The reason f o r t h e a d m i n i s t r a t i o n  the p r e s e n t study was t o determine whether s u b j e c t s either the extraversion Results  and n e u r o t i c i s m  o f the EPI i n  differed  dimension o r the n e u r o t i c i s m  as  along  dimension.  from a number o f p r e v i o u s s t u d i e s have i n d i c a t e d t h a t s c o r e s on  t h e s e two dimensions, e s p e c i a l l y t h e e x t r a v e r s i o n to performance on v e r b a l  s c a l e , were r e l a t e d  l e a r n i n g and memory t a s k s .  The EPI was used  i n t h e p r e s e n t experiment t o determine whether an a l t e r n a t i v e e x p l a n a t i o n based on p e r s o n a l i t y d i f f e r e n c e s c o u l d be advanced t o account f o r any  d i f f e r e n c e s found between t h e t h r e e weight groups on t h e experimen-  t a l measures.  The l a c k o f a s i g n i f i c a n t  d i f f e r e n c e between groups on  e i t h e r p e r s o n a l i t y dimension i n d i c a t e d t h a t t h e s i g n i f i c a n t  difference  between groups on t h e expectancy change t a s k was not a r e s u l t o f a. p r i o r i d i f f e r e n c e s between groups on e x t r a v e r s i o n This  finding also detracts  and/or  from a p o s s i b l e a l t e r n a t i v e  explanation  based on p e r s o n a l i t y d i f f e r e n c e s f o r d i f f e r e n c e s r e p o r t e d obese and normal s u b j e c t s  neuroticism.  between  i n previous i n v e s t i g a t i o n s .  S i n c e r e s u l t s from a number o f e a r l i e r i n v e s t i g a t i o n s had i n d i cated  that  scores  on t h e EPI were r e l a t e d t o performance on v e r b a l  l e a r n i n g and memory t a s k s , neuroticism  the r e l a t i o n s h i p o f e x t r a v e r s i o n and  t o performance on t h e two e x p e r i m e n t a l tasks  present study was i n v e s t i g a t e d i n d e p e n d e n t l y o f weight  used i n t h e  classification.  There were no s i g n i f i c a n t d i f f e r e n c e s between i n t r o v e r t s and e x t r a v e r t s or between n e u r o t i c s  and normals on any o f the e x p e r i m e n t a l measures  f o r e i t h e r t h e expectancy change t a s k o r t h e p a i r e d a s s o c i a t e task.  S i m i l a r l y , when s u b j e c t s were d i v i d e d i n t o f o u r  learning  personality  51  groups ( n o r m a l - i n t r o v e r t s , n o r m a l - e x t r a v e r t s ,  neurotic-introverts,  n e u r o t i c - e x t r a v e r t s ) t h e r e were a g a i n no s i g n i f i c a n t  differences  between t h e groups on any o f t h e performance measures f o r the two experimental  tasks.  The l a c k o f s i g n i f i c a n t  a l i t y groups on t h e t r a n s f e r l i s t somewhat i n c o n s i s t e n t w i t h  d i f f e r e n c e s between p e r s o n -  of the p a i r e d a s s o c i a t e t a s k i s  r e s u l t s from e a r l i e r s t u d i e s which have  found d i f f e r e n c e s between p e r s o n a l i t y groups on s i m i l a r t a s k s i n v o l v i n g competitive and  word l i s t s ,  Howarth, (1969).  present  e.g., A l l s o p p and Eysenck (1974), Bone (1971),  However, the f a c t t h a t t h e sample used i n t h e  i n v e s t i g a t i o n was n o t random s i n c e s u b j e c t s were s e l e c t e d on  the b a s i s o f recent weight h i s t o r y may account f o r these d i s c r e p a n c i e s . General The  Discussion experimental  some support  f i n d i n g s i n the present  i n v e s t i g a t i o n provide  f o r the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n t h e o r y based on  the r e s u l t s o f t h e expectancy change t a s k but i n d i c a t e t h a t obese subjects  i n future research  should be c l a s s i f i e d on t h e b a s i s o f  r e c e n t weight h i s t o r y and c o n s i s t e n c y S e l f - r e p o r t data were o b t a i n e d  o f t h e overweight c o n d i t i o n .  f o r a l l subjects  of t h e i r l i v e s when they had been overweight.  concerning  the periods  There were s i g n i f i c a n t  d i f f e r e n c e s between t h e t h r e e weight groups f o r a l l f o u r l i f e sampled i n d i c a t i n g t h a t weight d i f f e r e n c e s between t h e t h r e e  periods groups  extended much f u r t h e r than t h e two-year p e r i o d used f o r e x p e r i m e n t a l c l a s s i f i c a t i o n of subjects. would p r o b a b l y  Further  s p e c u l a t i o n based on these  data  be i n a p p r o p r i a t e because s u b j e c t s were not asked t o  g i v e any i n d i c a t i o n o f t h e degree o f overweight and a l s o  subjects'  responses on these items were based on s e l f - p e r c e p t i o n s o f overweight  52  which are o f t e n q u i t e d i f f e r e n t normative data.  from an o b j e c t i v e assessment based  S u b j e c t s were a l s o asked to i n d i c a t e i f they were  p r e s e n t l y on a d i e t .  Subjects  r e s t r i c t i n g t h e i r food i n t a k e might  viewed as hungry and p o s s i b l y below t h e i r b i o l o g i c a l s e t p o i n t s .  ence between groups might be more important  differ-  than r e c e n t weight h i s t o r y  p r o v i d e an a l t e r n a t i v e i n t e r p r e t a t i o n f o r the d i f f e r e n c e found  between obese and  f l u c t u a t o r s u b j e c t s on the expectancy change t a s k .  S i m i l a r numbers of f l u c t u a t o r and obese s u b j e c t s r e p o r t e d t h a t  they  were p r e s e n t l y d i e t i n g ; thus, an e x p l a n a t i o n of t h i s e x p e r i m e n t a l i n g based on d i f f e r e n c e s i n e a t i n g p a t t e r n s would be The  be If  more obese than f l u c t u a t o r s u b j e c t s were p r e s e n t l y d i e t i n g , t h i s  and  on  numbers of s u b j e c t s who  find-  inappropriate.  i n d i c a t e d they were p r e s e n t l y on a d i e t i n  the a v e r a g e , f l u c t u a t o r and obese groups were r e s p e c t i v e l y , 1, 12, A g a i n t h i s i n f o r m a t i o n was i n d i c a t e the n a t u r e The  obtained  or the extent  from s e l f - r e p o r t data and  of these  g e n e r a l i z a b i l i t y o f the p r e s e n t  the sample used i n the i n v e s t i g a t i o n was  all  s u b j e c t s i n t h i s study had v o l u n t e e r e d  dietary restrictions.  between 18-25  y e a r s of age.  p e r s o n a l i t y and  pants were aware t h a t the i n v e s t i g a t i o n was  other  sample was  i n v e s t i g a t i o n s of experimental  normal i n d i v i d u a l s , and  Also,  to p a r t i c i p a t e i n an had  exper-  completed a  q u e s t i o n n a i r e on r e c e n t weight h i s o t r y (Appendix A) so t h a t  In most r e s p e c t s the p r e s e n t  d i d not  r e s t r i c t e d to p a r t i c i p a n t s  were female, c o l l e g e s t u d e n t s  and  partici-  concerned w i t h body weight.  comparable t o those used i n  d i f f e r e n c e s between obese  and  the s e l e c t i o n of t h i s sample ensured t h a t  m e a n i n g f u l comparisons c o u l d be made between the r e s u l t s of t h i s t i g a t i o n and  9.  f i n d i n g s i s l i m i t e d i n that  who  iment on body b u i l d , b e h a v i o r ,  and  r e s u l t s from p r e v i o u s  studies.  inves-  53  Although t h e obese s u b j e c t s  i n t h e p r e s e n t i n v e s t i g a t i o n were o v e r -  weight a c c o r d i n g t o t h e e x p e r i m e n t a l c r i t e r i a  o f most o t h e r  investiga-  t i o n s i n t h i s a r e a , i t may be the case t h a t t h e i n c l u s i o n o f more subj e c t s who were h i g h l y overweight would produce somewhat d i f f e r e n t r e s u l t s i n i n v e s t i g a t i o n s of t h i s s o r t . t h a t d e f i n i t e l y obese s u b j e c t s  Some r e s e a r c h e r s have found  behave d i f f e r e n t l y from moderately o v e r -  weight i n d i v i d u a l s i n a number o f e x p e r i m e n t a l s i t u a t i o n s 1972;  Rodin, 1975).  Results  from these s t u d i e s  (Nisbett,  have i n d i c a t e d  that  extremely overweight i n d i v i d u a l s behave s i m i l a r l y t o average i n d i v i d u a l s i n s i t u a t i o n s i n v o l v i n g prominent e x t e r n a l  stimuli.  In the present  i n v e s t i g a t i o n c o r r e l a t i o n s between t h e degree of overweight as measured by t h e t r i c e p s s k i n f o l d and t h e e x p e r i m e n t a l measures i n d i c a t e d  that  degree o f overweight was p o s i t i v e l y r e l a t e d t o some measures o f p e r f o r mance on t h e e x p e r i m e n t a l t a s k s f o r s u b j e c t s group, i . e . , e r r o r s on t h e l a s t <. t r i a l s paired  30 cards o f t h e expectancy change  t o c r i t e r i o n and i n t r a l i s t associate  task,  i n t r u s i o n s on t h e f i r s t  list  task,  of the  and t h e t o t a l number o f e r r o r s and i n t r a l i s t  i n t r u s i o n s on t h e t r a n s f e r l i s t research  i n t h e c o n s i s t e n t l y obese  of the paired  associate  task.  Future  i n t h i s a r e a might i n c l u d e groups o f b o t h moderately o v e r -  weight and h i g h l y overweight i n d i v i d u a l s t o determine whether degree o f obesity  i s r e l a t e d to the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n e f f e c t .  example, extremely overweight s u b j e c t s  may have more d i f f i c u l t y i n  s u p p r e s s i n g potent responses than moderately overweight Implications  For  subjects.  f o r Treatment  Other i n v e s t i g a t o r s  (Singh, 1973; S i k e s ,  somewhat d i f f e r e n t i m p l i c a t i o n s  1974) have d i s c u s s e d  of the stimulus-binding  and t h e  the  54  d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n t h e o r i e s f o r t h e treatment o f obese individuals. concentrate  According  to the stimulus-binding  on i d e n t i f y i n g e n v i r o n m e n t a l s t i m u l i which e l i c i t  p r i a t e e a t i n g responses and attempting more a p p r o p r i a t e  eating behavior  response- i n h i b i t i o n theory concentrate  view, treatment  The d e f i c i t - i n -  i n d i c a t e s t h a t treatment e f f o r t s  responses w i t h o t h e r b e h a v i o r .  inappro-  t o modify t h e environment so t h a t  w i l l take p l a c e .  on response t e n d e n c i e s  should  and attempt t o r e p l a c e  should  inappropriate  A l s o , i f obese people have more  diffi-  c u l t y than average i n d i v i d u a l s i n i n h i b i t i n g an ongoing response, i t would seem t h a t treatment procedures aimed at d i s c o n t i n u i n g t h e e a t i n g response e a r l i e r i n a meal would be q u i t e e f f e c t i v e .  For instance,  obese i n d i v i d u a l s c o u l d be i n s t r u c t e d t o p l a c e a p p r o p r i a t e  portions of  food on t h e i r p l a t e s p r i o r t o a meal r a t h e r than h e l p i n g themselves t o food a t t h e t a b l e .  A l l other  food should be out o f s i g h t .  When t h e  food on t h e p l a t e has been consumed, t h e overweight i n d i v i d u a l would be  instructed, to leave the d i n i n g area.  I f , i n f a c t , t h e overweight  c o n d i t i o n i n obese i n d i v i d u a l s i s a t l e a s t i n p a r t due t o t h e i r suming more food a t r e g u l a r meals than i s n e c e s s a r y t o s a t i s f y  contheir  a p p e t i t e s , then t h e use o f t h i s procedure would seem t o be q u i t e effective.  T h i s t e c h n i q u e aimed a t r e d u c i n g  overeating  i s one o f a  number of procedures i n c l u d e d i n t h e b e h a v i o r a l treatment program o u t l i n e d by S t u a r t  (1967) which was designed b o t h t o l i m i t  mental s t i m u l i which e l i c i t  environ-  i n a p p r o p r i a t e e a t i n g responses and t o  r e p l a c e response h a b i t s which a r e c o n t r i b u t i n g t o the overweight condition.  The r e s u l t s from both t h e p r e s e n t  i n v e s t i g a t i o n and o t h e r  s t u d i e s have i n d i c a t e d t h a t t h e r e a r e b e h a v i o r a l d i f f e r e n c e s between  55  obese i n d i v i d u a l s who a r e c o n s i s t e n t l y overweight and those who a r e h i g h l y v a r i a b l e and a l s o between obese i n d i v i d u a l s who a r e extremely overweight and those who a r e moderately overweight. t a l r e s e a r c h on subgroups  Further  experimen-  o f obese i n d i v i d u a l s and the t r a n s l a t i o n o f  r e s e a r c h f i n d i n g s i n t o p o t e n t i a l l y e f f e c t i v e treatment procedures f o r i n d i v i d u a l c l i e n t s might  result  outcomes f o r obese p a t i e n t s .  i n an i n c r e a s e i n s u c c e s s f u l  treatment  For instance, according to the findings  of t h e p r e s e n t i n v e s t i g a t i o n treatment procedures aimed a t changing response t e n d e n c i e s would p r o b a b l y be more e f f e c t i v e w i t h c o n s i s t e n t l y obese than f l u c t u a t o r c l i e n t s . tions  Based on r e s u l t s from o t h e r i n v e s t i g a -  ( N i s b e t t , 1972; Rodin, 1975), an e f f e c t i v e treatment program f o r  moderately overweight i n d i v i d u a l s might mental s t i m u l i which e l i c i t  f o c u s on m o d i f y i n g t h e e n v i r o n -  inappropriate eating behavior while a d i f - ^  f e r e n t treatment emphasis may be more a p p r o p r i a t e w i t h extremely  obese  individuals. Future D i r e c t i o n s These a r e t e n t a t i v e s p e c u l a t i o n s and t h e need f o r more b a s i c r e s e a r c h on o b e s i t y i s g r e a t i f we a r e t o l e a r n more about t h i s  condi-  t i o n and t o g a i n knowledge about v a r i o u s types o f o b e s i t y which can be used i n f o r m u l a t i n g treatment programs f o r overweight p a t i e n t s . a r e s e v e r a l d i r e c t i o n s which f u t u r e r e s e a r c h might knowledge i n t h i s a r e a .  There  take to advance t h e  More i n v e s t i g a t i o n s c o u l d be run w i t h e x p e r i -  mental t a s k s which a l l o w a comparison  o f the p r e d i c t i o n s o f t h e  s t i m u l u s - b i n d i n g and d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n t h e o r i e s .  These  s t u d i e s c o u l d use s e v e r a l c a t e g o r i e s o f obese s u b j e c t s , e.g., c o n s i s t e n t l y overweight v e r s u s f l u c t u a t o r and extremely overweight v e r s u s  56  m o d e r a t e l y o v e r w e i g h t , i n a d d i t i o n t o a group o f average s u b j e c t s t o determine whether obese subgroups d i f f e r from each o t h e r and from t h e average group i n o t h e r e x p e r i m e n t a l s i t u a t i o n s .  Other s t u d i e s might  compare f l u c t u a t o r and c o n s i s t e n t l y obese s u b j e c t s on some o f t h e e x t e r n a l cue m a n i p u l a t i o n s p r e v i o u s l y used by S c h a c h t e r and o t h e r s . Whether an i n d i v i d u a l becomes o v e r w e i g h t o r n o t i s p r o b a b l y d e t e r mined by a host o f f a c t o r s i n c l u d i n g h e r e d i t y , d i e t  (which i s a f u n c t i o n  of s o c i o e c o n o m i c s t a t u s , e t h n i c i t y , and o t h e r v a r i a b l e s ) , and a c t i v i t y l e v e l .  O b e s i t y i s p r o b a b l y a c o m p l e x l y determined c o n d i -  t i o n and t h e p o p u l a t i o n o f overweight heterogeneous.  metabolism,  i n d i v i d u a l s seems t o be h i g h l y  The p r e s e n t i n v e s t i g a t i o n i n d i c a t e s t h a t weight  history  p l a y s an i m p o r t a n t r o l e i n t h e d e t e r m i n a t i o n o f b e h a v i o r i n obese individuals.  F u t u r e r e s e a r c h s h o u l d attempt t o i s o l a t e o t h e r f a c t o r s  which have a s i g n i f i c a n t b e a r i n g on t h i s  condition.  57  REFERENCES  A l l s o p p , J . F . and Eysenck, H.J. 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San Diego, C a l i f . : E d u c a t i o n a l and I n d u s t r i a l T e s t i n g S e r v i c e , 1968. Eysenck, M.W. A r o u s a l and speed of r e c a l l . The B r i t i s h J o u r n a l of S o c i a l and C l i n i c a l P s y c h o l o g y , 1975, 14, 269-277. Eysenck, M.W. E x t r a v e r s i o n , v e r b a l l e a r n i n g , and memory. B u l l e t i n , 1976, 83, 75-90.  Psychological  G r i n k e r , J . , Glucksman, M.L., H i r s c h , J . , and V i s e l t a e r , G. Time p e r c e p t i o n as a f u n c t i o n of weight r e d u c t i o n : A differentiation based on age a t onset of o b e s i t y . Psychosomatic M e d i c i n e , 1973, 35, 104-111. G r i n k e r , J . , H i r s c h , J . , and L e v i n , B. The a f f e c t i v e responses o f obese p a t i e n t s to weight r e d u c t i o n : a d i f f e r e n t i a t i o n based on age at onset o f o b e s i t y . Psychosomatic M e d i c i n e , 1973, 35_, 57-63. Haagen, C.H. Synonymity, v i v i d n e s s , f a m i l i a r i t y , and a s s o c i a t i o n v a l u e r a t i n g o f 400 p a i r s o f common a d j e c t i v e s . J o u r n a l of Psychology, 1949, 27, 453-463. H a r r i s , M.B. S e l f - d i r e c t e d program f o r weight c o n t r o l : J o u r n a l of Abnormal P s y c h o l o g y , 1969, 7Jt_, 263-270.  a pilot  study.  Howarth, E. E x t r a v e r s i o n and i n c r e a s e d i n t e r f e r e n c e i n p a i r e d - a s s o c i a t e learning. P e r c e p t u a l and Motor S k i l l s , 1969, 29, 403-406.  58  Johnson, W.G. E f f e c t of cue prominence and s u b j e c t weight on human f o o d - d i r e c t e d performance. J o u r n a l of P e r s o n a l i t y and S o c i a l P s y c h o l o g y, 1974, 29, 843-848. M a r a s c u i l o , L.A. Large-sample m u l t i p l e comparisons. B u l l e t i n , 1966, 65, 280-290.  Psychological  Melton, A.W. M a t e r i a l s f o r use i n e x p e r i m e n t a l s t u d i e s of l e a r n i n g and r e t e n t i o n of v e r b a l h a b i t s . Mimeographed M a n u s c r i p t , U n i v e r s i t y of M i s s o u r i , 1940. Metropolitan women.  L i f e Insurance Company. New weight standards f o r men S t a t i s t i c a l B u l l e t i n , 1959, 40, 1-4.  N i s b e t t , R.E. T a s t e , d e p r i v a t i o n , and weight determinants of behavior. J o u r n a l of P e r s o n a l i t y and S o c i a l P s y c h o l o g y, 10, 107-116.  and  eating 1968,  N i s b e t t , R.E. Hunger, o b e s i t y , and the v e n t r o m e d i a l hypothalamus. P s y c h o l o g i c a l Review, 1972, 79, 433-453. N u t r i t i o n Canada. N u t r i t i o n : Canada, 1973.  a National P r i o r i t y .  Ottawa: I n f o r m a t i o n  P e r v i n , L.A. R i g i d i t y i n n e u r o s i s and g e n e r a l p e r s o n a l i t y f u n c t i o n i n g . J o u r n a l of Abnormal and S o c i a l P s y c h o l o g y , 1960, 61, 389-395. P e t t , L.B. and O g i l v i e , G.F. The Canadian w e i g h t - h e i g h t survey, In J . Brozek (Ed.) Body Measurements and Human N u t r i t i o n . D e t r o i t : Wayne S t a t e U n i v e r s i t y P r e s s , 1956. P l i n e r , P.L. E f f e c t s of cue s a l i e n c e on the b e h a v i o r of obese and normal s u b j e c t s . J o u r n a l of Abnormal P s y c h o l o g y, 1973, 82, 226-232. P r i c e , J . and G r i n k e r , J . E f f e c t s of degree of o b e s i t y , food d e p r i v a t i o n , and p a l a t a b i l i t y on e a t i n g b e h a v i o r of humans. J o u r n a l of Comparative and P h y s i o l o g i c a l P s y c h o l o g y , 1973, 8_5, 265-271. Rodin, J . E f f e c t s of d i s t r a c t i o n on the performances of obese and normal s u b j e c t s . J o u r n a l of Comparative and P h y s i o l o g i c a l P s y c h o l o g y, 1973, 83, 68-75. Rodin, J . E f f e c t s of o b e s i t y and set p o i n t on t a s t e r e s p o n s i v e n e s s and i n g e s t i o n i n humans. J o u r n a l of Comparative and P h y s i o l o g i c a l P s y c h o l o g y, 1975, 89, 1003-1009. Rodin, J . , Herman, C P . , and S c h a c h t e r , S. E x t e r n a l s e n s i t i v i t y and obesity. In S. Schachter and J . Rodin ( E d s . ) , Obese Humans and Rats. Washington, D . C : Erlbaum, 1974.  59  Schachter, S. Some extraordinary facts about obese humans and rats. American Psychologist, 1971, 26, 129-144. Schachter, S. and Gross, L.P. Manipulated time and eating behavior. Journal of Personality and Social Psychology, 1968, H), 98-106. Schachter, S. and Rodin, J . Erlbaum, 1974.  Obese Humans and Rats.  Washington,  D.C.:  Seltzer, C.C. and Mayer, J . A simple c r i t e r i o n of obesity. Postgraduate Medicine, 1965, _38, A101-A107. Sikes, M.S.A. Behavioral c h a r a c t e r i s t i c s of the obese: the role of stimulus cues and response tendencies i n the control of behavior. Unpublished Doctoral Dissertation, University of Texas, 1974. Sikes, S. and Singh, D. Obesity and compliance. Psychonomic Society, 1974, 4-, 176.  B u l l e t i n of the  Singh, D. Role of response habits and cognitive factors i n determinat i o n of behavior of obese humans. Journal of Personality and Social Psychology, 1973, 27_, 220-238. Singh, D. and Sikes, S. Role of past experience on food-motivated behavior of obese humans. Journal of Comparative and Physiological Psychology, 1974, 86, 503-508. Stuart, R.B. Behavioral control of overeating. Therapy, 1967, j>, 357-365.  Behavior Research and  Stuart, R.B. and Davis, B. Slim Chance i n a Fat World. I l l i n o i s : Research Press, 1972.  Champaign,  Taylor, K.F. The relationships of introversion/extraversion and anxiety to lean body mass and reaction time. Unpublished Doctoral Dissertation, University of Alabama, 1971. United States Department of Health, Education, and Welfare, National Center for Health S t a t i s t i c s . Skinfolds, body g i r t h s , biacromial diameter, and selected anthropometric indices of adults, United States, 1960-1962. B u l l e t i n 35, Series 11, 1970. United States Public Health Service. Obesity and Health. (U.S.P.H.S. Publication No. 1485) Washington, D.C.: U.S. Government Printing O f f i c e , 1966. Wechsberg, J . 34-48.  La nature des choses.  The New Yorker, 1975, 51^, 23,  Winer, B.J. S t a t i s t i c a l p r i n c i p l e s i n experimental design. McGraw-Hill, 1962.  New  York:  60  Wollersheim, J.P. The effectiveness of group therapy based upon learning p r i n c i p l e s i n the treatment of overweight women. Journal of Abnormal Psychology, 1970, 7_6, 462-474. Wyden, P.  The Overweight  Society.  New York; William Morrow, 1965.  61  APPENDIX A I n i t i a l Weight NAME AGE  Questionnaire PHONE NUMBER  HEIGHT  WEIGHT  How would you d e s c r i b e your p h y s i c a l b u i l d a t the p r e s e n t time i n comparison t o o t h e r females o f a p p r o x i m a t e l y the same age? ( S e l e c t one) D e f i n i t e l y Underweight S l i g h t l y Underweight Average S l i g h t l y Overweight D e f i n i t e l y Overweight During t h e past two y e a r s what i s the l e a s t t h a t you have weighed (not i n c l u d i n g v a r i a t i o n s due t o s e r i o u s i l l n e s s or pregnancy)? How would you d e s c r i b e your p h y s i c a l b u i l d a t y o u r lowest weight i n comparison t o o t h e r females of a p p r o x i m a t e l y the same age? ( S e l e c t one) D e f i n i t e l y Underweight S l i g h t l y Underweight Average S l i g h t l y Overweight D e f i n i t e l y Overweight During the past two y e a r s what i s the most t h a t you have weighed (not i n c l u d i n g v a r i a t i o n s due t o s e r i o u s i l l n e s s o r pregnancy)? How would you d e s c r i b e your p h y s i c a l b u i l d at your h i g h e s t weight i n comparison t o o t h e r females o f a p p r o x i m a t e l y t h e same age? ( S e l e c t one) D e f i n i t e l y Underweight _ _ _ _ _ S l i g h t l y Underweight Average S l i g h t l y Overweight D e f i n i t e l y Overweight During t h e past two y e a r s what has your most f r e q u e n t weight been?  The i n f o r m a t i o n o b t a i n e d i n t h i s form w i l l be t r e a t e d e n t i r e l y c o n f i dentially. Names and t e l e p h o n e numbers w i l l be u t i l i z e d o n l y by t h e major i n v e s t i g a t o r t o c o n t a c t v o l u n t e e r s f o r the r e s e a r c h p r o j e c t . A l l data o b t a i n e d i n the study w i l l be a n a l y s e d u s i n g code numbers f o r i n d i v i d u a l p a r t i c i p a n t s t o guarantee anonymity. Penny Aves Department o f P s y c h o l o g y U n i v e r s i t y of B r i t i s h Columbia  62  APPENDIX B E x p e r i m e n t a l Consent Form  MAJOR INVESTIGATOR:  PENNY AVES  FACULTY SUPERVISOR:  DR. JERRY WIGGINS  S i n c e t h i s i s a study r e l a t i n g t o normal weight  f l u c t u a t i o n s , we  w i l l be u n a b l e t o i n c l u d e i n d i v i d u a l s who a r e now pregnant o r l a c t a t i n g or who have had any s e r i o u s i l l n e s s w i t h i n t h e past s i x months which might a f f e c t  t h e i r weight, e.g., h e p e t i t u s , d i a b e t e s , e t c .  I understand t h e above r e s t r i c t i o n s on e x p e r i m e n t a l s u b j e c t s . I have been informed o f t h e procedures i n v o l v e d i n t h i s  experiment  and agree t o p a r t i c i p a t e i n t h e t a s k s which have been d e s c r i b e d t o me. I a l s o u n d e r s t a n d t h a t I am f r e e t o t e r m i n a t e my p a r t i c i p a t i o n i n t h e experiment a t any time and f o r any reason.  SIGNATURE DATE  APPENDIX C Initial  and T r a n s f e r L i s t s used i n P a i r e d A s s o c i a t e Task  List A - Initial noxious western standard classic erect rounded yellow ample random overt zigzag basic  List  sudden bashful unshut prepared absent faultless insane evil double complete clumsy gloomy  B - Initial  i n j ured uphill feline overgrown yawning twisted joyous quiet vocal extinct wholesome stubborn  Pairs  Pairs  hidden careful adept distant grouchy fearless mammouth shining barren nomad devout little  L i s t A - Transfer noxious western standard classic erect rounded yellow ample random overt zigzag basic  List  clumsy double prepared bashful gloomy sudden unshut faultless complete evil absent insane  B - Transfer  i n j ured uphill feline overgrown yawning twisted joyous quiet vocal extinct wholesome stubborn  devout barren distant careful little hidden adept fearless nomad shining grouchy mammouth  64  APPENDIX D I n s t r u c t i o n s f o r the F i r s t  In appear.  List  of the P a i r e d A s s o c i a t e  Task  the space i n f r o n t of you a number of p a i r s of words w i l l When I s t a r t the machine, you w i l l see the f i r s t word and  about two seconds you w i l l second word.  after  see the f i r s t word a g a i n a l o n g w i t h the  Your t a s k w i l l be t o l e a r n t o connect o r a s s o c i a t e the  p a i r so when the f i r s t word appears you c a l l out the second word b e f o r e it  appears i n the space. W e ' l l go through the l i s t  once, and I'd l i k e you to j u s t watch  c a r e f u l l y and t r y t o remember as many p a i r s as you can.  A b l a n k space  w i l l appear a f t e r the l a s t p a i r and when the f i r s t word appears a g a i n I'd  l i k e you t o t r y and c a l l out the second word.  go through the l i s t  i n t h i s manner time a f t e r time u n t i l you've c o r -  r e c t l y a n t i c i p a t e d a l l of the words i n the l i s t trials.  W e ' l l c o n t i n u e to  f o r two c o n s e c u t i v e  Your s c o r e w i l l be based on the t o t a l number of c o r r e c t  responses you make so t r y and g i v e a response t o each s i n g l e word. There i s no p e n a l t y f o r g u e s s i n g so even i f you're unsure o f the response f e e l f r e e to guess because I'm of  i n t e r e s t e d as much i n the k i n d s  e r r o r s you make as i n the number of e r r o r s . Do you have any q u e s t i o n s ? Now,  try  w e ' l l go through t h e l i s t  t o remember the p a i r s .  you and you can s t a r t  once and j u s t watch c a r e f u l l y  When the l i s t  has gone by once, I ' l l  c a l l i n g out the r e s p o n s e s .  tell  Remember, t h e r e ' s no  p e n a l t y f o r wrong answers so guess i f you can. (The l i s t  i s p r e s e n t e d one time t o the s u b j e c t . )  Now  c a l l i n g out the responses.-  start  and  65  APPENDIX E Instructions  f o r the Transfer  L i s t of the Paired  Associate  Task  T h i s t a s k w i l l c o n s i s t o f t h e same items but the words w i l l be paired  differently.  As b e f o r e , go through the l i s t  c a r e f u l l y and t r y i n g t o remember t h e p a i r s .  once j u s t watching  A f t e r the f i r s t  exposure,  anytime you t h i n k you know t h e c o r r e c t response, j u s t c a l l i t o u t . Your s c o r e w i l l be based on t h e number o f c o r r e c t responses you make in  ten t r i a l s .  Remember, t h e r e ' s no p e n a l t y  f o r g u e s s i n g so i f you're  unsure o f a response f e e l f r e e t o guess because I'm i n t e r e s t e d as much in  t h e k i n d s o f e r r o r s you make as i n t h e number o f e r r o r s . (The  list  i s p r e s e n t e d one time t o t h e s u b j e c t ) .  Now s t a r t c a l l i n g out t h e r e s p o n s e s .  APPENDIX F Weight History and Medical Information Questionnaire  NAME  AGE  Do you f e e l that your present weight i s the best weight f o r you, or that you are over your best weight or under i t ? (Check one) Over best weight Under best weight Just right If you are over or under your best weight, indicate by how many pounds. Have you ever been overweight i n the past?  (Check one) Yes  No  If so, during which period(s) of your l i f e have you been overweight? (Check appropriate items) Childhood (1-8 years) Pre-Teens (9-11 years) Adolescence (12-18 years) Adult (19 years or l a t e r ) Whick of the following statements best describes your present eating behavior? (Check one) Am on a diet right now to lose weight Diet from time to time but not now Don't diet but never eat c e r t a i n fattening foods Once i n awhile cut down on fattening foods for a few days, but i n general pay no attention to weight Eat what I want with no concern about gaining weight If you diet, approximately how many times do you go on a diet during a year? Are you presently taking any form of medication? (Check appropriate items) Oral contraceptives Diet P i l l s Diuretics Other (please specify)  67  T y p i c a l l y , how long i t your m e n s t r u a l c y c l e ?  (days)  I f you a r e q u i t e i r r e g u l a r , what i s t h e range o f your c y c l e lengths? ( f o r example, 28-40 days) days t o  days  How many days has i t been s i n c e you l a s t (days)  s t a r t e d menstruating?  How many days has i t been s i n c e you l a s t (days)  f i n i s h e d menstruating?  APPENDIX G Summary of Results Mailed to Experimental Participants  Department of Psychology The University of B r i t i s h Columbia As you may  r e c a l l , several months ago you participated i n a  psychology experiment involving the relationship of body b u i l d to personality and behavior.  At that time I t o l d you that everyone  who  had helped me by p a r t i c i p a t i n g i n the experiment would receive a copy of the summary of the experimental r e s u l t s .  The data have now  been  analysed and the following section i s a summary of the experimental findings. Participants i n the study were divided into three groups on the basis of recent weight history and present weight c l a s s i f i c a t i o n s . These groups were consistently average, consistently overweight, and fluctuators (subjects whose weights over the past two years had  varied  between the average and overweight c l a s s i f i c a t i o n s ) . One  of the tasks you participated i n involved guessing the colors  of cards i n a stack.  The f i r s t 90 cards were 75% black and 25%  while the l a s t 30 cards were a l l red.  There were no  red  differences  between groups on the f i r s t part of the task; however, on the l a s t part (when a l l of the cards were red) there was  a s i g n i f i c a n t difference  between groups i n terms of the number of incorrect guesses made.  Con-  s i s t e n t l y overweight participants made s i g n i f i c a n t l y more errors than either average or fluctuator subjects.  This finding i s consistent  with the d e f i c i t - i n - r e s p o n s e - i n h i b i t i o n theory which maintains that  69  overweight people have greater d i f f i c u l t y i n changing established response tendencies than people of average weight. study, however, only people who  In the  present  had been consistently overweight for  the past two years experienced more d i f f i c u l t y i n changing an established response. The other experimental task involved learning two l i s t s , each consisting of 12 p a i r s of adjectives.  There were no s i g n i f i c a n t  differences between the three groups on performance measures for either l i s t : thus, i n t h i s s i t u a t i o n overweight subjects did not perform worse than average subjects when required to change established response tendencies.  Performance on t h i s task might have been i n f l u -  enced by other factors such as memory and imagery a b i l i t y which could have been more important i n this s i t u a t i o n than weight status. The personality questionnaire extraversion and neuroticism.  that you completed was  a measure of  Results from an analysis of these  scores indicated that there were no differences between the  three  weight groups on either extraversion or neuroticism.  This also i n d i -  cated that the difference i n performance on the card  color-guessing  task was  not due to personality differences on extraversion or  neuroticism between the three weight groups. The results from t h i s study indicate that i t i s important to consider recent weight history as well as present weight when i n v e s t i gating behavioral differences between overweight and normal i n d i v i d u a l s . Since the population of overweight individuals i s probably quite heterogeneous, i t i s l i k e l y that future research w i l l i d e n t i f y other  important f a c t o r s which d i f f e r e n t i a t e between groups  of  overweight  individuals. Though the r e s u l t s of t h i s p a r t i c u l a r experiment sufficient findings  i n themselves  t o permit a d i r e c t a p p l i c a t i o n  t o treatment procedures f o r overweight  hoped t h a t  are not  cumulative r e s u l t s  from i n v e s t i g a t i o n s  of t h e s e  individuals,  i t is  of t h i s type w i l l  soon b e g i n t o p r o v i d e important i n f o r m a t i o n which can be a p p l i e d f o r m u l a t i n g treatment programs f o r s p e c i f i c types of  overweight  individuals. Thank you a g a i n f o r your h e l p . Penny Aves  in  

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