UBC Theses and Dissertations
The relation of intelligence and the spread of effect Sutherland, Margaret Ruth
The problem investigated was the relation of intelligence to the spread of effect. A null hypothesis was set up that the spread pattern obtained from more intelligent subjects would not differ from that found in the less intelligent. Data were collected from two groups of thirty subjects each, one composed of "bright" and the other of "dull" students. All were pupils in Grades V, VI, and VII in the same school. The material was of the conventional type (word-stimulus, number-response) used in many "effect" experiments, but the typical procedure of rewarding correct responses with the announcement "right" and punishing wrong responses with the announcement "wrong" was modified by the omission of the announcement "wrong" during the course of the experiment. Serial position effects were obviated by making successive presentations of the list of stimulus words continuous, and by the length of the list. Favored responses were determined with the help of two presentations free from reward at the beginning of the experiment, and were eliminated from all calculations in order to establish a neutral baseline, which was determined by computing the percentage of total repetitions throughout the five presentations during which rewards were given. Gradients were plotted for each group from the percentages of repetition of rewarded responses and of repetitions one, two, and three steps before and after rewarded responses. The results are such that the null hypothesis must be accepted, that is, intelligence as measured by a standard test is not a variable factor in determining the spread of effect. Of the group differences found, none is statistically reliable. In so far as can be judged from a single experiment and within the parameters of that experiment, it is concluded that reward has equal effect on bright and dull students in a serial learning situation. The relatively low percentage levels of repetition as compared with those of previous studies is attributed to one of two factors, or possibly to a combination of both. In the first place, the method of assembling the data precluded favored responses from contributing to the gradients obtained, and so reduced the number of repetitions calculated. In the second, the word-list was of a length commonly used with subjects at the college level. From these facts, two tentative conclusions are reached. One, that to the extent that favored responses contribute to gradient data, levels of repetition obtained in a number of previous studies and attributed to the effect of reward, are spuriously high, and the influence of reward has been exaggerated. Two, the length of the test (in this case, the word-list), is a factor determining the influence of reward. It is thought that both of these conditions may be responsible, to a degree so far undetermined, for the results obtained in this study. Similarly to the levels of repetition found in each response category, the height of the established base-line is conspicuously lower than any previously adopted, and is noteworthy in its close approximation to the pure chance figure. It has been accounted for on the basis of elimination of favored responses and serial position effects, and would also have been affected by the factor of length of the word-list if this were an experimental variable. A summary consideration of the slope of the gradients from these data compared with gradient curves from previous studies where punishment in the form of the announcement "wrong," as well as reward, was administered to the subjects, revealed no consistent trends and added nothing conclusive by way of evidence on the influence of punishment in a learning situation, other than to emphasize the apparently varying roles this type of "punishment" can play, and the inadvisability of generalizing from the evidence thus far available on its modus operandi. In addition, the fact that unrewarded responses, which were not punished, in seven out of twelve categories were repeated less frequently than consideration of the neutral base-lines would have led one to expect requires explanation. It has been hypothesized that reward, in emphasizing the correct response, acts as a distraction on neighboring connections and thereby reduces their rate of repetition below the chance level. Suggestions were made for further research into the relation of intelligence and extent of spread; into the technique for establishing a base-line; into the factor of favored responses as unduly magnifying the effect of reward; and into the falling off of repetitions of unrewarded though unpunished responses below the obtained chance line.
Item Citations and Data