Grooming of conspecifics is thought to play an important social role among nonhuman primates, but the function and relative importance of such grooming among humans is unknown. Here the authors compare time spent grooming and conversing among six small-scale societies with grooming data from 69 nonhuman primate species. They test the hypothesis that conversation evolved among humans as an alternative way to obtain the social benefits (such as building and maintaining social alliances) of grooming in large groups.

This article tests hypotheses put forth by Murdock that female contribution to subsistence is associated with matrilocal residence.

This study examines the phenomenon of parallel-cousin marriage in patrilateral societies and it's relationship with Islamization.

This article focuses on deep Christianization as a new predictor of the decline of unilineal descent, previously attributed to stratification, statehood and commercialization. Deep Christianization is suggested to be the key cause of the decline in unilineal descent organization, though in complex traditional societies, this holds true only when Christianity is backed by the state.

This study investigates the relationship between domestic organization (i.e. family structure and size) and democracy at both the communal and supracommunal levels. The authors suggest that the prevalence of independent monogamous families in Europe in the Late Middle Ages may have facilitated the political evolution toward democracy.

This study investigates the relationship between cultural complexity and female premarital sexual freedom among foragers. To explain the decline of premarital sexual freedom, the authors discuss a few key trends such as the growth of social control and the decline of female status, as well as other variables such as intensification of foraging, social stratification, accumulation of wealth, political integration, and fixity of settlement. A model relating these variables is presented.

This article presents a review of theories relating postmarital residence with the gender division of labor. The author suggests that there will be an association between these two variables if societies with an extremely low female contribution to subsistence are contrasted with the rest of the world cultures. Results generally support this hypothesis.

This study focuses on the development of unilineal descent, reviewing previous theories and testing additional factors to explain the relationship between unilineal descent and unilocal residence. Results suggest four key factors leading to a low association between these two variables: insufficient alternatives to unilocal residence rule, instability of communal composition, absence of sedentary settlement pattern, and small average community size. A model linking all variables from the paper is presented.

This study discusses many variables that may influence the direction of altruism within a family. Significant relationships were found between paternity certainty, conjugal instability, marital residence, cross-cousin marriage preferences, and direction of altruistic behavior. Special emphasis is placed on the importance of the mother's brother.

This study proposes that polygyny, unilineal descent organization and large extended families could be regarded as universal negative predictors of communal democracy. Crosstabulations show that Christianity is positively associated with communal democracy and negatively associated with polygyny, and thus the authors suggest that Christianity influenced the development of democracy in Europe through its discouraging of polygyny and unilineal descent organization.