This study examines the variability of siestas across cultures and considers how factors including climate, subsistence type, and disease susceptability relate to the presence or absence of siestas. The author finds a significant relationship between siestas and the presence of malaria.

This study examines the variability of siestas across cultures and considers how factors including climate, subsistence type, and disease susceptability relate to the presence or absence of siestas. The author finds a significant relationship between siestas and the presence of malaria.

This exploratory study seeks to explain cassava production and processing in Africa by considering cultural, agronomic, and environmental data. After examining the descriptive results of the agricultural and social contexts of cassava use, the authors build upon Boserup's population density model (1965) to analyze their own hypothesized model of cassava's importance among the sampled societies.

This article builds on previous cross-country and cross-state research into Tightness-Looseness (TL) theory, which proposes relationships between the incidence of ecological threat and cultural tightness, as well as tightness’ downstream effects on belief in a moralizing high god, inter-group contact and authoritarian leadership. To evaluate the generalizability of TL theory beyond complex cultures, the authors test these relationships among 86 nonindustrial societies from the ethnographic record. A structural equation model is presented of the results for nonindustrial societies; it is generally in accord with previous findings from more complex societies. Because the nonindustrial sample is more variable, they also look at relationships between societal complexity and kinship heterogeneity, aspects that vary in nonindustrial societies.

The authors investigate environmental reasons for cross-cultural variation in the permissibility of cousin marriages. In particular, they test whether higher levels of pathogen prevalence and geographic isolation increase the likelihood that cousin marriage will be allowed. The authors' underlying theory is that cousin marriages provide protective homozygosity against some pathogens and provide more options when mate choices are limited.

The present study examines the relationship between pathogen prevalence and the domestic living-organization of 186 societies from the Standard Cross-Cultural Sample (SCCS). The measurement for pathogen stress consists of ten diseases described by Low (1991) and Caden and Steele (2013). These are dengue, typhus, plague, filariae, schistosomes, leishmanias, trypanosomes, malaria, leprosy, and spirochetes; the transmission for these diseases was contagious and/or mobile. The measurement for the living organization came from the 'Household Form' variable by Murdock and White (1969). The seven categories of household form variable were then re-coded into two variables. The first is modular, which includes single-family and family homestead. The second is communal and includes large communal structure, multifamily household, husband rotates, individuals, married, and husband separate. The findings offer support for the evolutionary hypothesis that modular living is adaptive because it may reduce pathogen stress. Specifically, pathogen stress is influential in the way people live.

The authors investigate environmental reasons for cross-cultural variation in the permissibility of cousin marriages. In particular, they test whether higher levels of pathogen prevalence and geographic isolation increase the likelihood that cousin marriage will be allowed. The authors' underlying theory is that cousin marriages provide protective homozygosity against some pathogens and provide more options when mate choices are limited.

This study explores ecological reasons that might explain why boys are mostly circumcised in tropical regions, particularly in Africa and the insular Pacific. The author postulates a long causal chain linking: 1) tropical climate to the growing of root and fruit crops; 2) the need to keep babies on mother's milk for as long as possible where the adult diet is lacking in protein; 3) a long post-partum sex taboo as a way to space births; 4) the practice of polygyny (and associated mother-child sleeping) in the face of a long sex taboo; 5) patrilocal residence; and 6) male initiation ceremonies which are believed to result from the combination of mother-child sleeping, the long poast-partum sex taboo and patrilocal residence.

This article focuses on the effect of environmental extremes and unpredictability on human behavior and reproductive strategies. Significant correlations were found between environmental extremes and unpredictability and several variables, including mobility, subsistence mode, and degree of polygyny.

This article examines the relationship between the tightness-looseness of a culture and the variation of COVID-19 cases and deaths through October 2020. With COVID-19 data retrieved from Our World in Data from 57 countries with tightness-looseness figures, the article found the cultures with high levels of tightness had fewer COVID-19 cases and deaths when compared to countries with high levels of looseness. Results suggest support of the evolutionary game theoretic model proposing that people in tight cultures may cooperate with more urgency when under collective threat than people in loose cultures.