Risky or not? : Characterizing Intuitive Health Risk Perception

Abstract

Previous research on health risk perception has revealed that people make snap judgments about potential health threats resulting from encounters with unacquainted people. Since HIV is still a dangerous threat in this context, many studies trying to broaden the understanding for the mechanisms underlying these judgments concentrated on this infectious disease. Recent research examined HIV risk perception by measuring neural responses while participants performed evaluations of HIV risk. Results showed that individuals perceived as 'risky' regarding HIV elicit a differential brain response compared to those perceived as ‘safe’. Since these brain responses preceded conscious thinking, the results supported the notion that these responses are based on intuitive processes. Although these findings provided elementary insights into the mechanisms underlying health risk perception, they have also raised new and important questions. Therefore, further studies were conducted for the present dissertation in order to establish a broader understanding of these processes.The first study addressed the question of whether previously observed differential ERP responses to unacquainted people being perceived as either ‘risky’ or ‘safe’ are specific to infectious, life-threatening diseases, such as HIV, or a general mechanism also triggered by life-threatening but non-infectious diseases. Therefore, dense sensor EEG was recorded while participants evaluated photographs of unacquainted individuals for either HIV or leukemia risk. While the ERP results replicated previous findings by revealing differential brain responses towards individuals perceived as risky in terms of HIV, no such differences could be found for leukemia risk. These findings suggest that intuitive risk judgments are at least in part specific to infectious diseases (e.g. HIV) rather than reflecting a generic response to terminal diseases.The second study addressed possible gender differences in intuitive impressions of HIV risk. Results from studies on evaluations of attractiveness and trustworthiness, a trait closely related to HIV risk ratings, revealed differences in ratings associated with the target’s gender as well as the perceiver’s gender. However, previous studies on HIV risk impressions only employed opposite-sex paradigms, precluding the investigation of possible gender differences. To address this issue, the second study used a paradigm containing same sex as well as opposite sex evaluations to investigate the effect of perceiver’s sex vs. target person’s gender. Female and male participants rated perceived HIV risk as well as seven risk-related trait characteristics for 120 photographs of target persons (half female and half male). Results revealed that male targets were perceived as more risky than female targets and that male perceivers gave higher HIV risk ratings for both male and female targets as compared to female perceivers. These findings support the notion that health risk perception actually is influenced by both the perceiver’s and the target’s gender.The third study investigated the influence of contextual cues on HIV risk perception. Towards this end, three groups of participants viewed one of three different picture sets. The first group viewed pictures of persons in a natural context. For the second and the third groups the same pictures were then edited to obtain two further picture sets: one set showing only the stimulus person, with the background masked, and one set only showing only the background, with the stimulus person masked. According to their stimulus set participants were asked to either evaluate the HIV risk of the presented person or the probability that a risky person might find themselves in the presented context. The HIV risk ratings for the original pictures and the person-only pictures were highly correlated. Furthermore, context ratings significantly predicted HIV risk impressions for the original pictures whenever the mean ratings of the context pictures opposed those of the person only pictures. Accordingly, contextual cues can influence the risk evaluation of a person in specific situations.The results reported in this dissertation provide important steps towards establishing a broader understanding of the underlying mechanisms of health risk perception which has been assumed to be part of the so-called behavioral immune system. This system gathers cues underlying snap judgments about unacquainted people. According to the reported findings, this system is not only able to make discriminations based on differentiations between healthy and sick people but also between infectious and non-infectious diseases. Furthermore, the system is dependent on the gender of the perceiver and the perceived target and occasionally even uses contextual information. These findings broaden the understanding of intuitive health risk perception and should be considered in theoretical models as well as in practical health promoting campaigns.