Does observing reciprocity or exploitation affect elevation, a mechanism driving prosociality?

Fitness is enhanced by determining when to behave prosocially. Elevation, an uplifting emotion elicited by witnessing exemplary prosociality, upregulates prosociality in the presence of prosocial others, as such contexts render prosociality profitable and/or antisociality costly. Prior research examines responses to a single highly prosocial individual. However, the profitability of enhancing prosociality hinges not only on potential interactions with a single actor, but also on the actions of others. Accordingly, information regarding how others respond to the prosocial exemplar may influence elevation elicitation and corresponding changes in prosocial motivation. If others reciprocate the exemplar's prosociality, or pay prosociality forward, this expands opportunities for the observer to profit by increasing prosociality, and thus could enhance elevation elicitation. Conversely, if others exploit the exemplar, this may diminish the profitability of prosociality, as the observer who acts prosocially may similarly be exploited and/or the resources with which the exemplar could reciprocate will be depleted. Conducting three online studies of Americans in which information regarding the responses of others to a prosocial exemplar was manipulated, we find that, against predictions, prosocial responses by the beneficiaries of prosociality generally do not enhance elevation among observers, whereas, consonant with predictions, antisocial responses markedly diminish elevation among observers.

Not Just Dead Meat: An Evolutionary Account of Corpse Treatment in Mortuary Rituals

Comparing mortuary rituals across 57 representative cultures extracted from the Human Relations Area Files, this paper demonstrates that kin of the deceased engage in behaviours to prepare the deceased for disposal that entail close and often prolonged contact with the contaminating corpse. At first glance, such practices are costly and lack obvious payoffs. Building on prior functionalist approaches, we present an explanation of corpse treatment that takes account of the unique adaptive challenges entailed by the death of a loved one. We propose that intimate contact with the corpse provides the bereaved with extensive veridical cues of death, thereby facilitating acceleration of a grieving process that serves to recategorize the deceased as no longer a relationship partner, opening the door to relationship replacement and a return to social functioning. The benefits of exposure to such cues are tempered by the costs of exposure to cues of disease risk, a balance that in part explains the relative rarity of highly invasive mortuary practices that exacerbate the latter factor. We conclude by discussing implications of our model for contemporary mortuary practices in the developed world.

Race Bias Tracks Conception Risk Across the Menstrual Cycle

Although a considerable body of research explores alterations in women's mating-relevant preferences across the menstrual cycle, investigators have yet to examine the potential for the menstrual cycle to influence intergroup attitudes. We examined the effects of changes in conception risk across the menstrual cycle on intergroup bias and found that increased conception risk was positively associated with several measures of race bias. This association was particularly strong when perceived vulnerability to sexual coercion was high. Our findings highlight the potential for hypotheses informed by an evolutionary perspective to generate new knowledge about current social problems—an avenue that may lead to new predictions in the study of intergroup relations.

Normative Bias and Adaptive Challenges: A Relational Approach to Coalitional Psychology and a Critique of Terror Management Theory

Adherence to ingroup ideology increases after exposure to death-related stimuli, a reaction that proponents of terror management theory (TMT) explain as a psychological defense against the uniquely human existential fear of death. We argue that existential concerns are not the relevant issue; rather, such concepts can be subsumed under a larger category of adaptive challenges that prime coalitional thinking. We suggest that increases in adherence to ingroup ideology in response to adaptive challenges are manifestations of normative mental representations emanating from psychological systems designed to enhance coordination and membership in social groups. In providing an alternative to TMT, we (1) explain why the theory is inconsistent with contemporary evolutionary biology, (2) demonstrate that mortality-salience does not have the unique evocative powers ascribed to it by TMT advocates, and (3) discuss our approach to coalitional psychology, a framework consistent with modern evolutionary theory and informed by a broad understanding of cultural variation, can be employed to help account for both the corpus of results in TMT research and the growing body of findings inconsistent with TMT's predictions.

The Effect of Age on Death Disgust: Challenges to Terror Management Perspectives

Proponents of Terror Management Theory (TMT) argue that many facets of disgust serve to defend against existential anxiety accompanying cognizance of one's mortality. Because the passage of time brings death closer, this view predicts that the intensity of disgust elicited by reminders of death should increase with age. Skeptical of TMT, we conducted Internet-based studies using the instrument created by TMT proponents. Results reveal that age is negatively, not positively, correlated with death disgust sensitivity, a pattern consistent with adaptive habituation rather than terror management. The same result was obtained using in-person administration of the instrument in Costa Rica, a society characterized by attitudes toward death that differ from those of the U.S. Additional work in Costa Rica demonstrated that, contrary to TMT predictions, attention to one's own death need not increase disgust reactions to the body or its products. Both the evocative power of death stimuli and the negative effects of age on death disgust are consistent with the argument that disgust is an adaptation motivating disease avoidance rather than a psychodynamic defense mechanism.

Luteal phase immunosuppression and meat eating

Immunosuppression during pregnancy makes the mother vulnerable to pathogens. Because meat is the principal source of ingestible pathogens, pregnancy raises the costs of meat eating. Natural selection has crafted a mechanism involving changes in nausea susceptibility and olfactory perception that reduces meat consumption during pregnancy. Evidence is presented showing that the luteal phase is marked by both immunosuppression and changes in nausea susceptibility and olfaction; meat consumption may be reduced during this period, suggesting a mechanism similar to pregnancy sickness. Constraints on compensatory increases in meat consumption outside of the luteal phase explain why women eat less meat than men. Meat is the principal target of acquired aversions. Women possess more aversions than men, suggesting that prophylactic mechanisms sometimes result in longstanding dietary changes. Reproductive immunosuppression explains many aspects of dietary behavior and sheds light on factors that may have contributed to gender-based divisions of labor during hominid evolution.