This article presents a model of cultural evolution simulating the accumulation of tools in specialized and non-specialized populations under different demographic and environmental scenarios. The model predicts that the relationship between population size and repertoire size is nonlinear and can differ between non-specialized and specialized populations. For small population sizes, the non-specialized populations maintain knowledge better and therefore reach higher average repertoire sizes. In large populations, specialized populations can reach higher average repertoire sizes. This is because non-specialized population's total repertoire size is limited by the capacity of individuals to accumulate knowledge of different skills, while in specialized populations, each individual needs to know only a fraction of the population's repertoire. However, the model also predicts that specialized populations are more susceptible to information loss due to their subdivision of knowledge, and this can be amplified by demographic and environmental factors. The authors also use ethnographic data to analyze the relationship between population size and degree of craft specialization of societies, and how this may be influenced by ecological factors.

Using cross-cultural comparative approaches among 249 cultures, this study explores the uniformity in human preference to concealing mating to others. The research questions guiding this study are: 1) Is the preference to conceal in legitimate mating a 'human universal'? and 2). What evolutionary pressures have originated this uniformity? The author proposes the ‘cooperation maintenance hypothesis’, which is built from three premises: sensory stimuli evoke sexual arousal in witnesses, humans are trying to exert control over their mating partner(s), and there is a need to foster within-group cooperation. This hypothesis suggests that concealing mating serves as a behavioral strategy to simultaneously retain control over mating partner(s) and foster cooperation with others. The author states that more analysis is needed to explain this behavior in other non-human species. The findings show support for the widespread pattern of concealment or attempts at concealment.

The present study examines the effect of social status on stature sexual dimorphism and whether food security acts as a mediator for this relationship. In societies where females have high social status and can exercise mate choice, there is lower stature sexual dimorphism. Food security enhances these results. Conversely, there is greater stature sexual dimorphism in societies where females have low social status and cannot exercise mate choice, especially if there is food insecurity.

Researchers used various hypotheses to determine if cross-country differences in trust and cooperation would predict prosocial COVID-19 responses and policies. Using individual surveys from 34,526 participants from 41 countries, there were no significant associations between trust and cooperation and prosocial behavior, motivation, regulation, or stringency of policies. While the researchers did find significant variation among cross-country individuals, these results were unable to predict country-level prosocial responses.

This study explores predictors of variation in two dimensions of marital residence patterns among hunter-gatherers: 1) the tendency toward patrilocality versus matrilocality and 2) the tendency toward unilocality versus bilocality.

The present research investigates food sharing and labor sharing practices of 98 nonindustrial societies. The aims are to: 1) document the frequency and scope of sharing, and 2) test the theory that greater sharing is adaptive in societies subject to more resource stress (including natural hazards).

This article uses the Standard Cross-Cultural Samples to test the relationship between disease and economic growth among sub-Saharan African societies. The authors suggest that a higher disease prevalence limits social integration and economic development since pre-colonial times. The variable measuring economic growth is the complexity of large or impressive structures. The hypotheses are that 1) pathogen stress is negatively correlated to the presence of complex buildings, and 2) pathogen stress is positively correlated to increased ethnic diversity. The results support both hypotheses, and there are additional results, like 1) the negative correlation between pathogen stress and current income per capita and 2) the negative correlation between the increased ethnic diversity and current income per capita. Overall, this article shows the robust relationship between disease and economic development.

This study relates the type of games present in a society to the level of cultural complexity. Authors use a "game-type combination scale" that categorizes societies as having: 1) games of physical skill only; 2) games of physical skill and games of chance; and 3) games of physical skill, games of chance, and games of strategy. Results show a relationship between the game-type combination scale and indicators of cultural complexity.

This article considers the consequences of modernization. Factor analysis is used to identify four stages of modernization: 1) changes in education, government, and trade; 2) changes in health, technology, and transportation; 3) changes in family, religion, and toilet; and 4) changes in behavior. The authors then consider five trends they expect to be associated with modernization and test whether they develop over the course of the four stages. Results indicate that these 5 trends—increased cultural complexity, female status, pacification, suicide, and social stress—are associated with only the first and fourth stages.

This article investigates a cultural patterning of altered states of consciousness. The authors use an ordinal variable for a society's trance type; its four levels are 1) trance, 2) trance and possession trance, 3) possession trance, and 4) neither type. Results suggest that trance type is associated with measures of societal complexity and subsistence economy. Regional differences and the effects of diffusion are also examined.