This article examines the relationship between pathogen stress and polygyny. Results indicate that there is a positive association between the two that is not confounded by geographic region, latitude, population density, male-male competition, or presence of brideprice. In particular, pathogen stress precicts higher levels of non-sororal polygyny and capturing women for wives or concubines.

In order to evaluate an adaptive justification for restriction of ritualized physical contact, the authors test association between three manifestations of physical interaction and prevalence of pathogens cross-culturally. Their expectation, supported by two of the three tested hypotheses, is that higher pathogen prevalence will lead to customs of restricted physical contact. Both cultural and biological evolution are suggested to be influential in selecting for physically intimate behaviors.

This paper seeks to identify how different practices of food sharing are related to one another, and the degree to which societies in North and South America may share practices with one another. The authors attempt this by using ethnographic literature to break sharing activities down into their constituent, multi-stage parts, and then comparing the prevalence of these parts and their relationships to one another. The study finds that the presence or absence of a distributor in a sharing activity, and who that distributor is, has a significant effect on how sharing is carried out. On the other hand, linguistic relationships between groups seem to have little impact on their sharing practices, and geographic proximity between groups only seems to have a significant effect on sharing practices in North America.

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 test the relationship between linguistic diversity and parasite richness, theorizing that anti-pathogen behaviors, such as the favoring of contact with a limited range of similar, nearby populations carrying the same suite of parasites and pathogens, will be selected for due to variability in immunobiological makeup between groups. As a result, cultural and gene pool isolation will be likely to further divide local parasite-host groups, generating language diversity as well as population divergence and new evolutionary forms among the parasites themselves. A significant positive correlation is found, which the authors suggest has important implications for future research regarding cross-cultural transmission and interaction.

This study focuses on the relationship between pathogen prevalence and mate selection. Results show that increased pathogen prevalence is significantly associated with an increased importance in the physical attractiveness of potential mates.

The authors test the relationship between disease prevalence and three different personality traits, with the expectation that pathogen load will be negatively associated with degree of sociosexuality, extraversion, and openness to experience. This prediction is supported by all three tests, which they theorize is an example of cultural behaviors adapting to reduce vulnerability to environmental risks.

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 article presents two evolutionary models that may explain relationships between war and socialization of children: the "environmentally contingent reproductive strategy" (ECRS) model put forward by Draper and Harpending (1982), and a model put forward by Carol and Melvin Ember. Results do not provide support for the hypotheses involving father-infant sleeping proximity derived from the ECRS model. The authors also find some inconsistencies with their own model.

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.