Which evolutionarily important social motives are cultural products about? Songs from the 2020 Billboard Hot 100 year-end chart were rated in terms of their relevance to the fundamental social motives. These songs were thought to be about seeking a romantic partner, followed by maintaining romantic relationships, breakups, and acquiring or maintaining status. Songs were thought to be least about avoiding infectious diseases and caring for children. Relative success of a song was found to be largely unassociated with which motive it reflects but significantly related to simplicity of the lyrics and prestige associated with the artist.

While more first-generation college (FGC) students are enrolling in college than ever before, these students still have poorer performance and higher rates of dropout than continuing-generation college (CGC) students. While many theories have predicted the academic performance of FGC students, few have taken into account the cultural transition to the university context. Similar to ethnic biculturals, FGC students must adjust to the middle-class culture of the university, and face challenges negotiating different cultural identities. I propose that FGC students who perceive their working- and middle-class identities as harmonious and compatible should have improved performance, compared to those that perceive their identities as incompatible. In three preliminary studies, I demonstrate that first-generation college students identify as social class bicultural, that integrated social class identities are positively related to well-being, health, and performance, that the effects of integrated identities on health and well-being are mediated by reduced acculturative stress. The current studies explore whether these effects persist across time and whether exposure to middle-class norms before college predict social class bicultural identity integration for FGC students. Results demonstrate that the effects of social class bicultural identity integration on depression and academic performance persist across time and that exposure to college graduates before college

predicts social class bicultural identity integration.

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.