Why do social perceivers use race to infer a target's propensity for criminal behavior and likelihood of re-offense? Life history theory proposes that the harshness and unpredictability of one's environment shapes individuals' behavior, with harsh and unpredictable ("desperate") ecologies inducing "fast" life history strategies (characterized by present-focused behaviors), and resource-sufficient and stable ("hopeful") ecologies inducing "slow" life history strategies (characterized by future-focused behaviors). Social perceivers have an implicit understanding of the ways in which ecology shapes behavior, and use cues to ecology to infer a target's likely life history strategy. Additionally, because race is confounded with ecology in the United States, American perceivers use race as a heuristic cue to ecology, stereotyping Black individuals as possessing faster life history strategies than White individuals. In the current project, I proposed that many race stereotypes about propensity for criminality and recidivism actually reflect inferences of life history strategy, and thus track beliefs about the behavioral effects of ecology, rather than race. In a series of three studies, I explored the relationship between ecology, race, and perceptions of criminal behavior. Participants in each experiment were recruited through an online marketplace. Findings indicated that (1) stereotypes regarding likelihood to engage in specific crimes were largely driven by beliefs about the presumed ecology of the offender, rather than the offender's race, such that Black and White targets from desperate (and hopeful) ecologies were stereotyped as similarly likely (or unlikely) to commit a variety of crimes; (2) lay beliefs about recidivism predictors likewise reflected inferences of life history strategy, and thus also tracked ecology rather than race; (3) when evaluating whether to release a specific offender on parole, participants placed greater importance on ecology information as compared to race information in a point allocation task, and prioritized ecology information over race information in a ranking task. Taken together, these findings suggest that beliefs about criminality and recidivism may not be driven by race, per se, but instead reflect inferences of how one's ecology shapes behavior. Implications of these findings for understanding and reducing racial bias in the criminal justice system are discussed.

Existing work suggests that intergroup negativity is caused by dissimilarities of values between groups. In contrast, I propose that incompatible values--regardless of whether they are similar or dissimilar--cause intergroup negativities. Because values act as cues to tangible goals and interests, groups' values suggest desired outcomes that may conflict with our own (i.e., incompatible values). The current study conceptually and empirically disentangles value-dissimilarity and value-incompatibility, which were confounded in previous research. Results indicated that intergroup negativities were strongly predicted by value-incompatibility, and only weakly and inconsistently predicted by value-dissimilarity. I further predicted that groups' values cue specific threats and opportunities to perceivers and that, in reaction to these inferred affordances, people will experience threat-relevant, specific emotional reactions (e.g., anger, disgust); however, results did not support this prediction. I also predicted that, because the inferred threats that groups pose to one another are not always symmetric, the negativities between groups may sometimes be asymmetric (i.e., Group A feels negatively toward Group B, but Group B feels neutral or positively toward Group A). This prediction received strong support. In sum, reframing our understanding of values as cues to conflicts-of-interest between groups provides principles for understanding intergroup prejudices in more nuanced ways.

Why are human societies so psychologically diverse? The discipline of behavioral ecology is rich in both theory and data on how environments shape non-human animal behavior. However, behavioral ecological thinking has not received much attention in the study of human cultural psychological variation. I propose that ecological relatedness—how genetically related individuals are to others in their proximate environment—is one aspect of the environment that shapes human psychology. I present three studies here that examine the influence of ecological relatedness on multiple aspects of psychology. In the first study, I find that higher levels of ecological relatedness at the nation level is associated with a greater willingness to put oneself at risk for others, greater localized trust, and a stronger sense of belonging to one’s community. In the second and third studies, using experimental manipulations of perceived ecological relatedness, I examine the effects of ecological relatedness on helping behavior across situations, monetary sharing on a dictator game, interpersonal judgments, and alloparenting behaviors. I find that individuals led to perceive higher ecological relatedness became more sensitive to need in potential helping situations. The implications of ecological relatedness for thinking about psychological variation across groups are discussed.

The broaden-and-build theory of positive emotion suggests that positive emotions should broaden thought and behavior repertoires in order to develop lasting resources. In the social domain, this means deploying a variety of affiliative strategies in order to build cooperative relationships. A functionalist perspective on positive emotion suggests that different positive emotions should have distinct effects on these affiliative mechanisms. This study elicited awe, amusement, pride or a neutral control in pairs of same sex strangers. They then completed an open-ended "getting to know you" conversation, which were recorded and coded for affiliative behaviors—smiling, laughter, mimicry, and asking questions. After, they rated their perception of the other as complex and how much they liked each other. Then they played the prisoner's dilemma game. Results indicate that there was a significant mediated effect such that being in the pride condition predicted greater smiling, and smiling predicted cooperation on the prisoner's dilemma. This was true both when an individual's own smiling was predicting their cooperative behavior and when their partner's smiling was predicting their cooperative behavior. However, these effects were only seen in female dyads, not male dyads. There was also a significant mediated effect such that pride led women to ask more questions, which led partners to like each other more. Additionally, awe led to greater mimicry in men, which in turn led to greater cooperation. In women, awe led to greater perception of the other as complex. Overall, these results indicate that there are broaden and build effects of positive emotions, but these are specific to both the emotion and the sex of the interaction members. This is also the first study to demonstrate both an actor and a partner effect of smiling on cooperation in a prisoner’s dilemma. An important area for further inquiry will be the interaction of emotion and sex in predicting social behavior. While sex differences in responding to threats have been characterized by the “tend and befriend” versus “fight or flight” action patterns, a similar approach may also need to be developed for sex differences in response to opportunities.

Negative behaviors targeting gay men and lesbians range from violent physical assault to avoiding social or physical contact, with very different implications for those targeted. However, existing theoretical accounts of sexual prejudices are unable to differentially predict these various behaviors, leaving a large theoretical hole in the literature and hindering the design of effective interventions. I propose (a) that homosexuality and pro-gay ideology are conceptualized by many lay persons as contaminants analogous to infectious diseases and (b) that anti-gay behaviors can thus be viewed as strategic attempts to prevent, contain, treat, or eradicate the "pathogens" of homosexuality and pro-gay ideology. In three preliminary studies I demonstrate that sexually prejudiced individuals do view homosexuality and pro-gay ideology as contagious, and that sexually prejudiced people report being more likely to engage in aggressive (versus avoidant) anti-gay behavior in conditions that predict an aggressive pathogen-combating response – highly interconnected social networks. The current study explores the effect of a social network manipulation on actual behavioral responses to a gay (versus straight) interaction partner. In this study I show that sexually prejudiced participants engage in more aggression towards a gay partner compared to a straight partner under a highly interconnected network manipulation.

Attachment relationships serve a variety of important functions for infants and adults. Despite the importance of attachment relationships in adults, the mechanisms that underlie the formation or maintenance of these kinds of relationships outside of romantic relationships remains chronically understudied. The current research investigated whether the mechanism of synchrony, which is associated with attachment formation in the parent-infant literature, may still be tied to attachment in adults. To measure this association, these studies showed participants videos to prime synchrony, and then measured activation of attachment concepts in a word completion task. The results of Experiment 1 showed that attachment style moderated the effects of the video prime such that those who were securely attached showed activation of attachment concepts while watching the Synchrony video. Those with a preoccupied attachment style showed activation of attachment concepts when they viewed the Asynchrony video. Those with a dismissive attachment style showed an unhypothesized activation of social distance concepts when viewing the Synchrony video. Experiment 2 suggested an overall effect of the Synchrony video on activation of attachment concepts. However, there was no effect of attachment style on these results. Limits of these studies and future directions are discussed.

Life History Theory suggests that, in order to maximize reproductive fitness, individuals make trade-offs between allocating resources to mating and parenting. These trade-offs are influenced by an individual's sex, life history strategy, and environment. Here, I explored the usefulness of a Life History Theory framework for understanding endorsement of child support laws. This study experimentally manipulated sex ratio, and gathered information about participants' endorsement of child support, sexual restrictedness, and mate value. As predicted, women endorsed child support more than men, whereas men favored greater restriction of child support in the form of required paternity testing. However, in general, results do not support an effect of sex ratio, sexual restrictedness, or mate value on endorsement of child support. Results suggest sensitivity to exploitation in a male-biased sex ratio, reflected by an increase in men's endorsement of paternity testing requirements under a male-biased sex ratio prime. Women, on the other hand, report especially unfavorable beliefs toward paternity testing in a male-biased sex ratio. Although results of the current study are mixed, there remains much to be gained from applying an evolutionary perspective to understanding variability in endorsement of child support.

The current research seeks to examine whether individuals display or downplay intelligence in various mating contexts. I hypothesized that both men and women should display fluid intelligence when attempting to attract a potential long-term partner, and that only men should display fluid intelligence when attempting to attract a potential short-term partner. Contrary to predictions, I find that men perform worse at a fluid intelligence test when motivated to attract a long-term partner. With respect to crystallized intelligence, I predicted that both men and women should display crystallized intelligence when attempting to attract a potential long-term partner, but women should downplay crystallized intelligence when attempting to attract a potential short-term partner. However, there were no effects of mating contexts on displays of crystallized intelligence.

This project uses a functional approach to understand how members of stigmatized groups perceive emotional expressions on others' faces. The project starts from the premise that different groups are seen to pose different threats to others, and thus different groups face prejudices colored by different, specific negative emotions. For example, prejudice toward Black men is driven largely by fear, whereas prejudice toward obese people is driven largely by disgust. Members of these groups may thus come to be "expert" in perceiving fear or disgust in others' faces, depending on the specific emotional prejudices others feel toward their group. Alternatively, members of these groups may be biased to over- or under-perceive these emotional expressions on others' faces. I used a functional approach to predict that, if a Black man believes that seeing others' fear expressions will be useful to him, he will tend to overperceive fear on others' faces, whereas if an obese man believes that seeing others' disgust expressions will be useful to him, he will tend to overperceive disgust on others' faces. If, however, it is not considered useful to perceive these prejudicial emotions on others' faces, Black men and obese people will tend to underperceive these emotional expressions. This study recruited Black men, overweight men, and a group of comparison men. All participants completed an emotion detection task in which they rated faces on whether they expressed fear, disgust, or no emotion. Participants were randomly assigned to complete this emotion detection task either before or after a questionnaire designed to make salient, as well as to measure, participants' beliefs about others' prejudices and stereotypes of their group. Finally, participants completed a set of measures tapping predicted moderator variables. Results suggested that a) Black men tend to be less sensitive perceivers of both fear and disgust on others' faces than are other groups, unless prejudice is salient, and b) variables that would guide the functionality of perceiving others' prejudicial emotional expressions (e.g., belief that prejudice toward one's group is justified, belief that group status differences are legitimate, belief that one can manage stigmatizing interactions, stigma consciousness, and emotion-specific metastereotypes of one's group) do predict differences among Black men in perceiving these emotions on others' faces. Most results for overweight participants were null findings. The results' implications for the psychology of detecting prejudice, and emotional expressions more broadly, are discussed.

National surveys indicate that Americans hold greater prejudice toward atheists than many other historically stigmatized groups. The religious prosociality perspective posits that people will demonstrate prejudice toward anyone who does not believe in a monitoring and punishing god, including atheists, because of the perception that those who lack belief in a monitoring and punishing god cannot be trusted to act in a prosocial manner. The sociofunctional perspective posits that people will demonstrate distinct forms of prejudice toward individuals who present certain types of threats to the group, and previous research suggests that atheists are perceived as posing a threat to group values. In the current study, participants rated targets whose values largely matched their own values more favorably than targets whose values did not largely match their own values. Also, participants rated both targets who believed in a monitoring and punishing god and targets who believed in a god who does not monitor nor punish more favorably than atheist targets. These judgments spanned a variety of measures, including emotional reactions to the target, judgments of target traits, and preferred social distance from the target. Results were consistent with the sociofunctional perspective but did not support the religious prosociality perspective.