In this article the researcher conducted five different studies on in-group or "we-group" vs out-group or "they-group" discrimination practices. Two previous hypotheses are re-examined, the pathogen stress hypothesis and the rice-wheat hypothesis, in order to explain heightened ingroup-outgroup differentiation, before turning to overarching geographical hypothesis. Each of the five studies look at a different group of societies cross-culturally, ending in an index of intergroup discrimination by individuals across 222 countries in study 5. All five studies conclude that differentiation between us and them varies based on geographical location and more specifically, along latitude.

This article explores the following questions: What environmental and cultural factors might explain variation in prejudice across cultures? Do these factors explain the intention to vote for nationalist politicians? The authors perform seven studies, focusing on the link between cultural tightness and the rise of prejudice in cultures. They theorize that cultural tightness is positively correlated with the rise of prejudice against people perceived as disrupting the social order. From this theory, they suggest three hypotheses: 1) cultural variation in tightness is related to cultural variation in prejudice, 2) cultural tightness is related to the support for nationalist politicians, and 3) cultural tightness is a link between ecological threats and prejudice. The results support these hypotheses, offering a cultural evolutionary perspective on prejudice.

The study proposes a Bayesian modeling framework to analyze and examine the mapping between emotions and speech prosody. The models are fitted to a large collection of emotional prosody recordings, and the study reveals that the mapping varies across corpora, individuals, cultures, and sexes. The study suggests that models accounting for mapping differences across these factors outperform models assuming a global mapping.

This article uses alliance theory and kin selection theory to examine the relationship between consanguineous marriage and descent system. The author argues that there is no relationship between the severity of incest taboos and the rules of exogamy or endogamy. A series of testable hypotheses regarding incest, marital, and descent rules are presented.

This study focuses on cultural preferences for skin pigmentation. Findings indicate a general preference for lighter pigmentation in women. Cultural and biological theories are offered, and the authors suggest the skin-pigmentation preference is an instance of gene-culture coevolution. Areas for further research to explain the relationship of this finding with other features of society are suggested.

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.

Controlling on a wide range of factors, this article examines the relationship between precolonial systems of leadership succession and contemporary deforestation rates. In a study of areas within the boundaries of 649 precolonial societies, the article finds that areas where local leaders were appointed by social standing were more likely to have poorer institutions governing forest management. The authors emphasize the importance of local governance over forest management and argue that precolonial institutions of leadership still have a bearing on current systems of forest management.

As the title suggests, the authors of this article investigate whether political repression motivates or deters anti-government violence. Through multinational analyses of 101 nationally representative samples from Africa, Asia, and Latin America, they find that highly politically repressed individuals are more likely to participate or have intentions to participate in anti-government violence.

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.