Inter-group variation is greater in humans than in any other animal, and scholars continue to debate the cause of this diversity. Two competing explanatory models of human variation emphasize either (1) ecological differences and "evoked" culture or (2) population-level effects of cultural transmission. The former emphasizes mechanisms that operate within a single generation, while the latter emphasizes cumulative cultural history operating over many generations. To test these competing models, the authors measured the relative power of ecological variables as compared to culture history to predict behavioral variation in 172 western North American tribes. Culture history is subdivided into culture phylogeny (based on language phylogeny) and spatial distance.

In this study, the authors analyze relationships between witchcraft accusations and the gender of the accused. They find that men are most often accused of witchcraft in their sample of 54 Bantu or Bantoid societies, and are particularly more likely to be accused of witchcraft by unrelated or blood-related individuals or in disputes over wealth or prestige. On the other hand, women are more likely to be accused of witchcraft in affinal relationships, particularly husbands and co-wives, and in situations related to fertility or relationships. Elderly women were also more likely to be accused of witchcraft than elderly men. The authors also examined outcomes of witchcraft accusations, finding that 81% of cases resulted in a negative outcome for the accused. They suggest that competition underlies accusations of witchcraft.

This article employs a phylogenetic approach to explore traits that might be associated with the cultural transmission of the "witchcraft phenotype" across Bantoid and Bantu ethnolinguistic groups. The authors define the witchcraft phenotype as a set of interlinked traits related to witchcraft beliefs within a society, showing both cross-cultural similarities and regional variations. Despite the widespread historical and geographical presence of witchcraft beliefs, little is known about their evolution and transmission. The article's analysis focuses on the possible ancestral transmission of these traits and their coevolution. The authors suggest that witchcraft phenotypes are often intertwined with beliefs in ancestors, spirits, gods, and other supernatural entities, and like other cultural traits, they can evolve through various mechanisms. Their findings indicate support for phylogenetic transmission of some traits, such as the use of poison to detect witchcraft guilt, but show that other factors such as age and gender do not show evidence of historical transmission.

Using data on 25 ethnolinguistic groups in the Austronesian language family, this study asks: does cooperation in games vary with socio-ecological differences across cultural groups? The authors suggest that cultural groups that cooperate in subsistence, tend to have intergroup conflict and less intragroup conflict, and are less socially stratified are more likely to play cooperative games compared to other groups. While the results support the first three hypotheses, there is insufficient data to support the fourth. The authors conclude that games serve as training ground for group norms and values.

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 Trivers-Willard hypothesis posits that concentrations of human milk immune factors vary with maternal condition (maternal diet diversity and body mass index) and the sex of the infant. Using linear mixed-effects models to analyze 358 milk samples from 10 international sites, the authors find minimal support for the Trivers-Willard hypothesis; only one immune factor, IgG, exhibited a significant relationship.

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.