UBC Theses and Dissertations

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UBC Theses and Dissertations

Disease avoidance mechanisms and their implications Duncan, Lesley Alexandra


Pathogens and parasites posed significant fitness threats to our ancestors. As a consequence of these enduring threats, there are likely to have evolved a set of cognitive and affective systems designed to facilitate the behavioral avoidance of disease-causing pathogens and their carriers – including individuals who are already infected. The behavioural immune system is a suite of attentional, affective, cognitive, and behavioural responses which function to decrease the probability of contracting pathogens by activating aversive responses to indirect cues that heuristically connote the presence of infectious agents. These cues, however, are at best probabilistically related to the actual presence of pathogens, because the majority of pathogens are too small to be detected. Specific hypotheses were developed to test the influence of pathogen avoidance motivations on three aspects of social cognition. The first focuses on individual variation in concerns with pathogens. The second topic addressed pertains to the types of physical features that act as triggers to activate the behavioural immune system. The third topic addressed the extent to which pathogen avoidance mechanisms play a role in the way we learn cues which connote pathogen presence. In conclusion, this thesis provides evidence which is consistent with the operation of a psychological system which functions to prevent the transmission of infectious threats. The results reported here represent both a substantial contribution to our understanding of the subtle effects of these processes on early cognitive process and a starting point for the application of our existing knowledge to solving real world problems that have great potential for providing social and theoretical rewards.

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