[show abstract][hide abstract] ABSTRACT: According to a "parasite stress" hypothesis, authoritarian governments are more likely to emerge in regions characterized by a high prevalence of disease-causing pathogens. Recent cross-national evidence is consistent with this hypothesis, but there are inferential limitations associated with that evidence. We report two studies that address some of these limitations, and provide further tests of the hypothesis. Study 1 revealed that parasite prevalence strongly predicted cross-national differences on measures assessing individuals' authoritarian personalities, and this effect statistically mediated the relationship between parasite prevalence and authoritarian governance. The mediation result is inconsistent with an alternative explanation for previous findings. To address further limitations associated with cross-national comparisons, Study 2 tested the parasite stress hypothesis on a sample of traditional small-scale societies (the Standard Cross-Cultural Sample). Results revealed that parasite prevalence predicted measures of authoritarian governance, and did so even when statistically controlling for other threats to human welfare. (One additional threat-famine-also uniquely predicted authoritarianism.) Together, these results further substantiate the parasite stress hypothesis of authoritarianism, and suggest that societal differences in authoritarian governance result, in part, from cultural differences in individuals' authoritarian personalities.
PLoS ONE 01/2013; 8(5):e62275. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: A study (n = 411) investigated the relationship between chronic individual differences in germ aversion and sociosexual attitudes (short-term mating orientation, long-term mating orientation, and anticipated future sexual promiscuity), and also tested whether the magnitudes of these relations differ depending on the temporary perceptual salience of disease threat. Results revealed person-by-situation interactions. When the threat of disease was temporarily salient, germ aversion correlated negatively with short-term mating orientation and with future sexual promiscuity, and correlated positively with long-term mating orientation; these effects were either weaker or nonexistent under control conditions. These effects emerged most clearly among women.
Personality and Individual Differences 01/2013; 54(1):103–108. · 1.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: Different groups, because they are perceived to pose different threats, elicit different prejudices. Collective action by disadvantaged groups can amplify the perception of specific threats, with predictable and potentially counterproductive consequences. It is important to carefully consider the threat-based psychology of prejudice(s) before implementing any strategy intended to promote positive social change.
Behavioral and Brain Sciences 11/2012; · 18.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: At least four conceptually distinct mechanisms may mediate relations between parasite-stress and cultural outcomes: genetic evolution, developmental plasticity, neurocognitive flexibility, and cultural transmission. These mechanisms may operate independently or in conjunction with one another. Rigorous research on specific mediating mechanisms is required to more completely articulate implications of parasite stress on human psychology and human culture.
Behavioral and Brain Sciences 04/2012; 35(2):91-2. · 18.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: Because immunological defence against pathogens is costly and merely reactive, human anti-pathogen defence is also characterized by proactive behavioural mechanisms that inhibit contact with pathogens in the first place. This behavioural immune system comprises psychological processes that infer infection risk from perceptual cues, and that respond to these perceptual cues through the activation of aversive emotions, cognitions and behavioural impulses. These processes are engaged flexibly, producing context-contingent variation in the nature and magnitude of aversive responses. These processes have important implications for human social cognition and social behaviour-including implications for social gregariousness, person perception, intergroup prejudice, mate preferences, sexual behaviour and conformity. Empirical evidence bearing on these many implications is reviewed and discussed. This review also identifies important directions for future research on the human behavioural immune system--including the need for enquiry into underlying mechanisms, additional behavioural consequences and implications for human health and well-being.
Philosophical Transactions of The Royal Society B Biological Sciences 12/2011; 366(1583):3418-26. · 6.23 Impact Factor
[show abstract][hide abstract] ABSTRACT: Like many other animals, human beings engage in behavioral defenses against infectious pathogens. The behavioral immune system consists of a suite of psychological mechanisms that (a) detect cues connoting the presence of infectious pathogens in the immediate environment, (b) trigger disease-relevant emotional and cognitive responses, and thus (c) facilitate behavioral avoidance of pathogen infection. However, the system responds to an overly general set of superficial cues, which can result in aversive responses to things (including people) that pose no actual threat of pathogen infection. In addition, the system is flexible, such that more strongly aversive responses occur under conditions in which perceivers are (or merely perceive themselves to be) more vulnerable to pathogen infection. Recent research reveals many provocative implications—for the experience of disgust, for extraversion and social interaction, for xenophobia and other prejudices, and for the origins of cultural differences.
Current Directions in Psychological Science 04/2011; 20:99-103. · 3.93 Impact Factor
[show abstract][hide abstract] ABSTRACT: What are the origins of cultural differences in conformity? The authors deduce the hypothesis that these cultural differences may reflect historical variability in the prevalence of disease-causing pathogens: Where pathogens were more prevalent, there were likely to emerge cultural norms promoting greater conformity. The authors conducted four tests of this hypothesis, using countries as units of analysis. Results support the pathogen prevalence hypothesis. Pathogen prevalence positively predicts cultural differences in effect sizes that emerge from behavioral conformity experiments (r=.49, n=17) and in the percentage of the population who prioritize obedience (r=.48, n=83). Pathogen prevalence also negatively predicted two indicators of tolerance for nonconformity: within-country dispositional variability (r=-.48, n=33) and the percentage of the population who are left-handed (r=-.73, n=20). Additional analyses address plausible alternative causal explanations. Discussion focuses on plausible underlying mechanisms (e.g., genetic, developmental, cognitive).
Personality and Social Psychology Bulletin 03/2011; 37(3):318-29. · 2.22 Impact Factor
[show abstract][hide abstract] ABSTRACT: Humans likely evolved precautionary systems designed to minimize the threats to reproductive fitness posed by highly interdependent ultrasociality. A review of research on the self-protection and disease avoidance systems reveals that each system is functionally distinct and domain-specific: each is attuned to different cues; engages different emotions, inferences, and behavioral inclinations; and is rooted in somewhat different neurobiological substrates. These systems share important features, however. Each system is functionally coherent, in that perceptual, affective, cognitive, and behavioral processes work in concert to reduce fitness costs of potential threats. Each system is biased in a risk-averse manner, erring toward precautionary responses even when available cues only heuristically imply threat. And each system is functionally flexible, being highly sensitive to specific ecological and dispositional cues that signal greater vulnerability to the relevant threat. These features characterize a general template useful for understanding not only the self-protection and disease avoidance systems, but also a broader set of evolved, domain-specific precautionary systems.
[show abstract][hide abstract] ABSTRACT: Regional differences in disease prevalence are associated with a wide array of cross-cultural differences. However, the complex relationships among culture, disease, and other ecological variables remain underinvestigated. Future research into the origins of cultural differences will benefit from the availability of a numerical index identifying the extent to which infectious diseases have been historically prevalent within regions defined by geopolitical borders. This article introduces such an index. This index is based on disease prevalence data obtained from old epidemiological atlases and is calculated for 230 geopolitical regions (mostly nations) around the world.
Journal of Cross-Cultural Psychology 11/2010; 41(99). · 1.42 Impact Factor
[show abstract][hide abstract] ABSTRACT: An experiment (N = 28) tested the hypothesis that the mere visual perception of disease-connoting cues promotes a more aggressive immune response. Participants were exposed either to photographs depicting symptoms of infectious disease or to photographs depicting guns. After incubation with a model bacterial stimulus, participants' white blood cells produced higher levels of the proinflammatory cytokine interleukin-6 (IL-6) in the infectious-disease condition, compared with the control (guns) condition. These results provide the first empirical evidence that visual perception of other people's symptoms may cause the immune system to respond more aggressively to infection. Adaptive origins and functional implications are discussed.
[show abstract][hide abstract] ABSTRACT: Maslow's pyramid of human needs, proposed in 1943, has been one of the most cognitively contagious ideas in the behavioral sciences. Anticipating later evolutionary views of human motivation and cognition, Maslow viewed human motives as based in innate and universal predispositions. We revisit the idea of a motivational hierarchy in light of theoretical developments at the interface of evolutionary biology, anthropology, and psychology. After considering motives at three different levels of analysis, we argue that the basic foundational structure of the pyramid is worth preserving, but that it should be buttressed with a few architectural extensions. By adding a contemporary design feature, connections between fundamental motives and immediate situational threats and opportunities should be highlighted. By incorporating a classical element, these connections can be strengthened by anchoring the hierarchy of human motives more firmly in the bedrock of modern evolutionary theory. We propose a renovated hierarchy of fundamental motives that serves as both an integrative framework and a generative foundation for future empirical research.
Perspectives on Psychological Science 05/2010; 5(3):292-314. · 4.89 Impact Factor
[show abstract][hide abstract] ABSTRACT: When encountering individuals with a potential inclination to harm them, people face a dilemma: Staring at them provides useful information about their intentions but may also be perceived by them as intrusive and challenging-thereby increasing the likelihood of the very threat the people fear. One solution to this dilemma would be an enhanced ability to efficiently encode such individuals-to be able to remember them without spending any additional direct attention on them. In two experiments, the authors primed self-protective concerns in perceivers and assessed visual attention and recognition memory for a variety of faces. Consistent with hypotheses, self-protective participants (relative to control participants) exhibited enhanced encoding efficiency (i.e., greater memory not predicated on any enhancement of visual attention) for Black and Arab male faces-groups stereotyped as being potentially dangerous-but not for female or White male faces. Results suggest that encoding efficiency depends on the functional relevance of the social information people encounter.
Social psychological and personality science. 04/2010; 1(2):182-189.
[show abstract][hide abstract] ABSTRACT: Fundamental motives have direct implications for evolutionary fitness and orchestrate attention, memory, and social inference in functionally specific ways. Motivational states linked to self-protection and mating offer illustrative examples. When self-protective motives are aroused, people show enhanced attention to, and memory for, angry male strangers; they also perceive out-group members as especially dangerous. In contrast, when mating motives are aroused, men show enhanced attention to and memory for attractive members of the opposite sex; mating motives also lead men (but not women) to perceive sexual arousal in attractive members of the opposite sex. There are further functionally specific consequences for social behavior. For example, self-protective motives increase conformity among both men and women, whereas mating motives lead men (but not women) to engage in anticonformist behavior. Other motivational systems trigger different adaptive patterns of cognitive and behavioral responses. This body of research illustrates the highly specific consequences of fitness-relevant motivational states for cognition and behavior, and highlights the value of studying human motivation and cognition within an evolutionary framework.
Current Directions in Psychological Science 02/2010; 19(1):63-67. · 3.93 Impact Factor
[show abstract][hide abstract] ABSTRACT: The parasite-stress model of human sociality proposes that humans' ontogenetic experiences with infectious diseases as well as their evolutionary historical interactions with these diseases exert causal influences on human psychology and social behavior. This model has been supported by cross-national relationships between parasite prevalence and human personality traits, and between parasite prevalence and societal values. Importantly, the parasite-stress model emphasizes the causal role of non-zoonotic parasites (which have the capacity for human-to-human transmission), rather than zoonotic parasites (which do not), but previous studies failed to distinguish between these conceptually distinct cate- gories. The present investigation directly tested the differential predictive effects of zoonotic and non-zoonotic (both human-specific and multihost) parasite prevalence on personality traits and societal values. Supporting the parasite-stress model, cross-national differences in personality traits (unrestricted sexuality, extraversion, openness to experi- ences) and in societal values (individualism, collectivism, gender equality, democratiza- tion) are predicted specifically by non-zoonotic parasite prevalence.
[show abstract][hide abstract] ABSTRACT: Four thoughtful commentaries identify important issues and insights pertaining to the pyramid of needs presented by Kenrick, Griskevicius, Neuberg, and Schaller (2010, this issue). Here, we offer additional thoughts on some of these issues and insights, with an emphasis on the logical implications that result from an evolutionary analysis of fundamental human needs.
Perspectives on Psychological Science 01/2010; 5(3):335-337. · 4.89 Impact Factor
[show abstract][hide abstract] ABSTRACT: We propose that consanguineous marriages arise adaptively in response to high parasite prevalence and function to maintain coadapted gene complexes and associated local adaptation that defend against local pathogens. Therefore, a greater prevalence of inbreeding by consanguineous marriage is expected in geographical regions that historically have had high levels of disease-causing parasites. Eventually such marriages may, under the contemporary high movement of people with modern transportation, jeopardize the immunity of those who practice inbreeding as this leads to an increased susceptibility to novel pathogens. Therefore, a greater frequency of inbreeding is expected to predict higher levels of contemporary mortality and morbidity from infectious diseases. This parasite model of human inbreeding was supported by an analysis involving 72 countries worldwide. We found that historically high levels of pathogen prevalence were related positively to the proportion of consanguineous marriages, and that a higher prevalence of such marriages was associated with higher contemporary mortality and morbidity due to pathogens. Our study addresses plausible alternative explanations. The results suggest that consanguineous marriage is an adaptive consequence of historical pathogen ecologies, but is maladaptive in contemporary disease ecologies.
[show abstract][hide abstract] ABSTRACT: Prejudice against elderly people (“ageism”) is an issue of increasing social concern, but the psychological roots of ageism are only partially understood. Recent theorizing suggests that ageism may result, in part, from fallible cue-based disease-avoidance mechanisms. The perception of subjectively atypical physical features (including features associated with aging) may implicitly activate aversive semantic concepts (implicit ageism), and this implicit ageism is likely to emerge among perceivers who are especially worried about the transmission of infectious diseases. We report an experiment (N = 88) that provides the first empirical test of this hypothesis. Results revealed that implicit ageism is predicted by the interactive effects of chronic perceptions of vulnerability to infectious disease and by the temporary salience of disease-causing pathogens. Moreover, these effects are moderated by perceivers' cultural background. Implications for public policy are discussed.
Analyses of Social Issues and Public Policy 11/2009; 9(1):97 - 115.