This article examines reasons for participation in warfare and tests a hypothesis concerning cultural rewards from war. Data supports this hypothesis. The authors also critique alternative theories of participation in warfare that draw on group selection and the risk of punishment.

Using Bayesian phylogenetic analysis, the authors ask: "Do cultural traits exhibit different histories of transmission?". They explore two competing models regarding Iranian tribal textile tradition. First, the "hierarchically integrated system hypothesis" emphasizes the importance of a core tradition and peripheral traits that are shared among contemporaneous populations. Second, the "multiple coherent units hypothesis" suggests that the groups of cultural traits have different transmission histories. The results show more support towards the "multiple coherent units hypothesis", specifically that pile-weave designs emerge as a cultural unit with a unique phylogenetic history compared to other textile characters.

The present research investigates the theory of universality in form and function in human song in a sample of people from 60 countries listening to music from 86 mainly small-scale societies. The aims are to document whether people 1) identify the social function of a song solely on form, 2) demonstrate form-function inferences, 3) use contextual aspects to distinguish song functions, and 4) use musical features to differentiate song functions. The authors claim support for the universal perception of song form-function in music listeners.

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.

Using t-test, generalized linear models (GLMs) and Bayesian regression models in a sample of 1188 pre-industrial societies, this study explores the research question: Why have foraging, horticulture, and pastoralism persisted into the 20th and 21st century? The authors test the marginal hypothesis and the oasis hypothesis of agricultural intensification. The first hypothesis suggests that foragers persisted because foragers predominantly inhabited marginal habitats that were typically unsuitable for agricultural purposes. The second hypothesis suggests that intensive agriculture emerged in regions characterized by limited biodiversity and a dependable water supply not reliant on local rainfall. In addition, the authors test whether specific kinds of biodiversity (elephants, malaria, and tsetse flies) correlate with agricultural intensification in African societies. The results support the marginal and oasis hypotheses, but only marginally support the African hypothesis, since only tsetse fly has a significant negative correlation to agricultural intensification.

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.