Testosterone has been hypothesized to help explain sex differences in pathogen disgust sensitivity (PDS), which is a measure of how intensely one experiences disgust toward pathogen threats. Guided by the sexual selection framework, researchers have theorized testosterone may downregulate PDS to facilitate mating effort. Yet, this relationship remains largely untested outside women samples. The present study (total N = 355) assessed salivary testosterone and PDS in three distinct populations: A sample of adults from Boston including 1) cisgender men (N = 116), 2) transmasculine adults on hormone therapy (N = 30), and 3) a longitudinal sample of juveniles and adolescents from Utila, Honduras (N = 209; 119 girls). Across all cohorts, testosterone showed no significant associations with PDS. Collectively, we found no evidence that testosterone levels meaningfully shape PDS, regardless of developmental stage, route, or level of hormone exposure.
Fertility has fallen below replacement across many contemporary societies while intentions to have children remain widespread. Economic and cultural explanations identify important correlates of this decline, but they do not specify the mating-market mechanisms through which reproductive outcomes are generated. This article advances a parameter-shift model of mating equilibria in contracepted, high-choice environments, extending explanations of fertility decline from fertility preferences to the formation and timing of stable pair-bonds. Drawing on parental investment theory and sexual selection, the model locates contemporary fertility decline within a historically novel mating ecology consolidated after the 1960s. Effective contraception, expanded female autonomy, and enlarged partner markets reduced kin and institutional constraints on mate selection, allowing female choice to operate at unprecedented scale under low pregnancy probability. Larger choice sets increase comparison and can alter female partner evaluation, reducing the proportion of men judged acceptable for long-term partnership even without a generalized increase in selectivity. The result is longer mate search and a lower equilibrium probability of forming stable reproductive unions within finite fertility windows. This fertility-reducing equilibrium configuration—termed the Female Choice Fertility Paradox—generates testable predictions regarding union timing, assortative concentration, mediation through partnership formation, and cultural moderation.
Dolls represent one of the most widespread and enduring material objects that humans create across societies. The pervasiveness of dolls can offer novel insights into the role of human material culture in processes of cultural evolution. While commonly considered children's toys and discussed in relation to childhood play, in many societies dolls are also employed for magical purposes. Here, we examine the dual use of dolls to inform us about the cultural evolution of supernatural beliefs and magic. We made use of the electronic Human Relations Area Files (eHRAF) to identify different types of dolls and their uses across societies in the Standard Cross-Cultural Sample (SCCS). Across 110 societies, two distinct doll types emerged, some for play, and others for magic. Furthermore, dolls are used in magic practices 1) as tools to punish adversaries, 2) for protection or healing, 3) to increase fertility, and 4) to embody spirits. In a Bayesian model with controls for spatial and cultural non-independence, we found that the presence of magic dolls was associated with greater cultural complexity, while toy dolls were not. This association was found across both explanatory and socially regulatory forms of magic. As dolls are used for both play and magic (mundane and supernatural domains), this study contributes to our broader understanding of how the function of cultural objects evolves in response to other societal changes.
