This article examines predictors of intimacy between husbands and wives. Emphasis is on equality of spouses. A causal model is presented.

Based on work by Rosenblatt (1966), this article tests a hypothesis relating sexual freedom to romantic love. Findings suggest a relationship between premarital and extramarital sexual permissiveness equality for women and men and romantic love.

Previous cross-cultural studies of romantic love have, in the authors' view, been plagued by vague definitions of the concept and a conflation of cultural, bio-psychological, and social factors. Thus, the authors distinguish between the social aspect of romantic love (which they argue is a universal human predisposition) and the variable cultural valuation of romance. In a large cross-cultural sample, the authors test the hypotheses that gender equality and family organization are important predictors of the cultural valuation of romantic love.

This paper presents research on the factors that promote romantic love as a basis for marriage in non-industrial societies. After a discussion of the previous literature on romantic love in ethnographic societies, the authors used the SCCS, EA, and data from eHRAF to create a data set of 109 cultures and then utilized multiple ordinal regression to test the relationship between different types of families and post-marital residence practices and the importance of romantic love in marriage. The findings show that monogamy is significantly correlated with romantic love, while nuclear family organization and neolocal post-marital residence are not significantly correlated. The presence of polygyny is found to lower the probability of romantic love being a basis for marriage. These findings contradict previous research, which found a relationship between non-neolocal post-marital residence and the presence of romantic love in marriage.

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.

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 the conditions under which slavery occurs in preindustrial societies. Results suggest that social stratification and the existence of open resources are both necessary conditions for the occurrence of slavery.