Across cultures, people find many of the same things funny. Competing theories of humor have been forwarded to account for this. Adopting a view of humor as an evolved response to benign violations, I argue that four comic themes characterize most humor across cultures: pain and misfortune, sex and obscenity, the foreign, and the sacred. I propose that each of these themes are ultimately grounded in our evolved psychology as universal pressure points that humor can tap into. I review 745 descriptions of humor in the ethnographic record of the ten hunter-gatherer societies in the Probability Sample Files (PSF) within the Human Relations Area Files (HRAF) World Cultures database, finding support for my account. I discuss the relevance of these findings for our understanding of the evolution and function of humor, arguing that humor evolved to signal and reinforce interpersonal trust and affiliation through reciprocal play with benign violations of socially charged norms and boundaries.
Humans tend to be prosocial towards in-group members, but often hostile towards out-group members. In line with ethology and evolutionary psychology, this study develops the concept of Durkheimian learning, meaning that groups actively integrate individuals by cultural transmission of behavioral norms. Yet humans might have genetically evolved predispositions for indoctrinability and constrained learning of what is adaptive for self-interested individuals living in groups. In-group prosociality might have coevolved with tendencies towards out-group rejection. The mechanism behind this outcome might have been cultural-group selection in combination with gene-culture co-evolution. The feasibility of the argument will be illustrated by two simulation experiments of a selfish-teamwork game. Inspired by the Price equation of multilevel selection, the simulations combine fuzzy group-boundaries and between-group competition with cooperative behavior and intergenerational cultural transmission of prosocial behavior within groups. Results show that group boundaries, e.g. due to cultural markers, can explain the evolution of cooperative behavior. However, efficient Durkheimian learning and intergroup competition might have accelerated its expansion, despite of considerable levels of between-group migration. This insight will be discussed in the light of recent arguments from cultural evolutionary psychology.
Humans tend to be prosocial towards in-group members, but often hostile towards out-group members. In line with ethology and evolutionary psychology, this study develops the concept of Durkheimian learning, meaning that groups actively integrate individuals by cultural transmission of behavioral norms. Yet humans might have genetically evolved predispositions for indoctrinability and constrained learning of what is adaptive for self-interested individuals living in groups. In-group prosociality might have coevolved with tendencies towards out-group rejection. The mechanism behind this outcome might have been cultural-group selection in combination with gene-culture co-evolution. The feasibility of the argument will be illustrated by two simulation experiments of a selfish-teamwork game. Inspired by the Price equation of multilevel selection, the simulations combine fuzzy group-boundaries and between-group competition with cooperative behavior and intergenerational cultural transmission of prosocial behavior within groups. Results show that group boundaries, e.g. due to cultural markers, can explain the evolution of cooperative behavior. However, efficient Durkheimian learning and intergroup competition might have accelerated its expansion, despite of considerable levels of between-group migration. This insight will be discussed in the light of recent arguments from cultural evolutionary psychology.
The relationship between facial expressions and facial shape is surprisingly understudied. We use facial videos and photographs, along with others' judgements, to investigate the interplay among facial morphology, dynamics, and perception. Facial expressions were quantified through Action Units (AUs) using the Facial Action Coding System. Facial shape was analysed using geometric morphometrics. Analysis of the relationships between 14 AUs and 13 morphological parameters revealed that women display more intense facial movements, but men exhibit a tighter link between facial movements and facial structures. Next, we used Principal Component Analysis for a broader categorisation. The principal components (PCs) of the AU data corresponded to groups of AUs, revealing specific facial expressions. Three of the expressions thus identified were the same in both sexes, while the fourth was sex specific. The PCs of the morphometric data were more mosaic in composition; however, one male and one female PC largely agreed, reflecting a similar facial-shape phenotype. In both sexes, this facial shape dimension was associated with the tendency to produce a Duchenne smile. In turn, the expression of a Duchenne smile systematically affected how people in the videos were judged by an independent panel on various attributes (e.g., generosity, trustworthiness, happiness). In men, a male-specific PC of the morphometric data corresponded to facial masculinity, as determined by Linear Discriminant Analysis. Men with more masculine facial shapes were more likely to produce lower-face anger expression. We conclude that natural facial expressions are to a certain extent related to facial morphology, especially in men.
People's perceptions of their mate value-a compilation of characteristics that are desirable to potential partners-functionally guide their mating behaviors. Hormonal contraceptives alter the hormonal profiles linked to some characteristics underlying women's mate value (e.g., fertility, sociality, potential parenting ability). Thus, relative to naturally cycling women, women using hormonal contraceptives may perceive such characteristics more negatively (due to suppressed fertility) or positively (due to possible bolstered sociality and/or potential parenting ability). The purpose of this research was to test these competing possibilities. Study 1a and 1b utilized samples of single, undergraduate women and newly married women, respectively, to test the association between hormonal contraceptive use and a commonly used proxy for self-perceived mate value-self-perceived mating success. Study1b additionally tested whether the association emerged independently of sexual frequency. Study 2 tested the robustness of the observed association, using a larger sample of single women and a measure assessing perceived characteristics underlying mate value rather than perceived mating success. We then conducted a mini-meta-analysis to estimate the average effect size for all relevant effect sizes available to date. Across studies, women using hormonal contraceptives rated mate-value-relevant traits and outcomes more positively than naturally cycling women. This association is not due to sexual motives or sexual behaviors. The current research adds to a growing literature revealing differences in mating and relationship psychology between women who do versus do not use hormonal contraceptives.
