One salient aspect of most world religions is an emphasis on reproductive morality—rules about which types of sexual behaviors and familiar structures are acceptable. In Chapter 1, I introduce the theoretical background of the dissertation, including the Reproductive-Religiosity Model. Then, in one theoretical paper (Chapter 2) and two empirical papers (Chapters 3 and 4), I consider the cultural and social implications of religious proscriptions on sexual behavior. In Chapter 2, I review the Reproductive-Religiosity Model, which posits that religions are especially attractive to people who desire monogamous, long-term mating strategies. I also discuss the implications of this model for cultural evolution. In Chapter 3, I look at the social implications of these religious proscriptions. That is, if restricted attitudes toward sexuality are strongly linked to religious belief, it follows that people’s stereotypes of religious people may track this relationship. Three studies showed that people tended to trust religious targets more than nonreligious targets, but that this effect seems to be due to inferences about religious targets’ reproductive strategies—that is, people trusted religious targets because they perceived them more likely to be interested in starting a family. In Chapter 4, I examine patterns of religiosity across the world through a rational choice lens, positing that people are more likely to be religious when religion can help them fulfill their goals. Analysis of two global datasets shows that men, more so than women, tend to be less religious in countries with greater gender equality. Finally, Chapter 5 summarizes results and discusses future directions for this line of research.

Anti-atheist prejudice is cross-culturally prevalent and marked by intuitive distrust. However, recent research suggests that, when social perceivers know additional relevant information about others (i.e., their reproductive strategies), this information overrides religious information and nonreligious targets are trusted as much as religious targets. That is, perceivers seem to use religious information as a cue to a specific set of behavioral traits, but prioritize direct information about these traits when available. Here, I use this framework to explore the possibility that atheists are viewed positively in certain circumstances. First, atheists might be viewed positively for certain purposes because of their perceived reproductive strategies, even while being trusted less. Second, atheists who are family-oriented do not sacrifice trust, but may still be viewed positively for other traits (i.e., open-mindedness, scientific thinking). Third, given the constraints religion often imposes on behavior, atheists might be trusted more in situations where these constraints interfere with religious people’s inclination to cooperate. I tested these hypotheses using fictitious social media profiles to examine social perception. The study had a 3 (Target Religion: Religious, Nonreligious, or Atheist) × 3 (Target Reproductive Strategy: No Information, Committed, Uncommitted) experimental design (N = 550). Contrary to my predictions, participants did not rate atheists and nonreligious targets as “fast” compared to religious targets. Consistent with predictions, however, atheists and nonreligious individuals were rated significantly higher on perceived open-mindedness and scientific thinking. Finally, atheist and nonreligious targets were trusted more in two of the three trust domains: trust with scientific findings that contradict their worldview and trust with a secret about a friend’s abortion. Further analyses compared patterns of responding for religious and nonreligious individuals, finding evidence for ingroup bias in most perceptions, but not all. Results suggest that perceptions of atheists are complex, but that atheists may, at least sometimes, be viewed favorably. Finally, these results point to the importance of reproductive strategy as a dimension of social perception, as this variable had a clear effect, independent of target religion, on the hypothesized perceptions.