This study is a comprehensive analysis of female and male genital mutilation/cutting (FGM/C and MGM/C) practices, including their history and socio-ecological correlates, using a phylogenetic cross-cultural framework. It employed two global ethnographic samples, the Ethnographic Atlas (EA) and the Standard Cross-Cultural Sample (SCCS), and two subsets of the phylogeny (supertree) of human populations based on genetic and linguistic data, to investigate the variables that may have led to the introduction of these practices, and to determine where and when they may have originated. The study suggests that MGM/C probably originated in polygynous societies with separate residence for co-wives, supporting a mate-guarding function, and that FGM/C likely originated subsequently and almost exclusively in societies already practicing MGM/C, where it may have become a signal of chastity. Both practices are believed to have originated multiple times, some as early as in the mid-Holocene (5,000–7,000 years ago). The study posits that GM/C co-evolves with and may help maintain fundamental social structures and that the high fitness costs of FGM/C are offset by social benefits, such as enhanced marriageability and social capital.

"Seven of Max Weber's ideal-typical specifications for 'rational bureaucracy' are reformulated as a system of three 'bureaucratic' and four 'rational' variables. It is proposed that (a) bureaucratic variables are positively associated; (b) rational variables are positively associated; but that (c) rational variables are negatively associated with bureaucratic variables." Hypotheses are supported.

Using a sample of 313 societies classified within 24 language phyla, authors put forward a statistical model based on climate data [specifically focused on the 10°C (50°F) winter temperature isotherm] to explain why dispersion of preindustrial language phyla is remarkably homogeneous even despite heterogeneous geographical dispersion of sampled preindustrial cultural groups. They suggest that temperature has been a barrier to migration.

The cross-cultural test on preindustrial societies is a very minor part of a larger work testing the theory that a psychological factor--need for achievement--plays a large role in understanding economic growth and decline. Most of the work focuses on countries and complex societies in the historical past.

This book chapter tests new and pre-existing theories (Horton, Field, Bacon et al.) for the cause of variation in drinking across cultures. Folktale content is used to test psychological variables more directly than has been done previously. Folktale content is analyzed programmatically with an acknowledged error level of up to one-third. Results lend support to Field's 1962 theory that loose social organization facilitates drinking.

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.

Researchers examined both why so many language are spoken today, and why they are so unevenly distributed geographically. Instead of looking at correlative tests, this study uses a process-based simulation model that attempted to predict both the number or precolonial languages in Australia as well as the number of languages per unit of land. The model was based upon three basic assumptions: 1) humans fill unoccupied spaces; 2) rainfall limits population density; 3) groups divide after reaching a maximum population. While researchers used the model strictly on the Australia continent, it was able to correctly explain 56% of spatial variation in language richness, and predict the total number of languages across the continent. The accuracy of this model concludes that climatic conditions and changes in group size are important factors in shaping language diversity patterns and therefore global human cultural diversity.

This article examines child-training through children's display of individualistic orientations (self-reliance, achievement, and general independence) and/or group orientations (responsibility, nurturance, and obedience). Five sub-categories measure whether each orientation is linked to a child's experience of general pressure or performance anxiety/conflict. Together, these orientations their sub-categories total 30 variables that were correlated; differences in gender were also examined. Results indicate that child-rearing pressure to act one way predicts pressure to act in other ways, and this pattern of interaction between variables did not vary by gender.

This study examines the relationship between disequilibrium and cognitive development using measurements of child-rearing, presence of high gods, and games of strategy.

This study examines the role of schooling in socialization processes and cultural complexity, seeking to understand whether schooling is correlated with these variables and/or affects them. The author concludes that school serves as a socializer for young children, a skill developer for older children, and a homogenizing force on societal child-rearing practices.