The authors predict that fitness outcomes will be negatively associated with spousal relatedness among foragers but positively associated among non-foragers, due to the greater social benefits of intensive kinship systems among non-foragers. Support is found for this hypothesis; however, an interaction effect is discovered with inbreeding, which appears to account for the variability in these relationships independent of subsistence activity. The authors qualify this support in order to explain why the incidence of cousin-marriage in non-foraging societies is not higher.

This book is a comprehensive analysis of many aspects of social structure including family, clan, community, kinship terminology, social organization, regulation of sex, incest taboos, and sexual choice.

This book examines male and female power in various kinship configurations. Variables for male dominance and female autonomy are associated with various political and social variables, such as political complexity and co-wife jealousy. Several hypotheses are supported.

This article uses alliance theory and kin selection theory to examine the relationship between consanguineous marriage and descent system. The author argues that there is no relationship between the severity of incest taboos and the rules of exogamy or endogamy. A series of testable hypotheses regarding incest, marital, and descent rules are presented.

While it is widely accepted that there are a multitude of variables that contribute to a society’s level of democracy, the authors of this study argue that the prevalence of consanguinity is one that is often overlooked. Using a sample of 70 nations, they tested the relationship between consanguinity (defined as marriage and subsequent mating between second cousins or closer relatives) and level of democracy (defined by both the Polity IV scale and the EIU Index) and found a significant negative relationship. Similarly, when controlled for a host of different variables in multiple regression analysis, the significant relationship between consanguinity and level of democracy held true.

This article presents a theory of evolutionary development of incest regulation, namely that as societal complexity increases the incest taboo will become less extensive. The author presents empirical support for this theory, though the association is not supported among simply structured societies. The role of descent type is also discussed.

This article investigates incest rules, proposing that they are instituted by rulers as a way of preventing wealth-concentration among non-ruling families. Three hypotheses are derived and supported with empirical analysis. Two alternative evolutionary hypotheses are discussed and dismissed by the author.

This study examines instances of group fission cross-culturally. Results suggest that internal political conflict and resource scarcity are the two most common causes of group fission. Results also suggest that group fission tends to occur along kin lines.

This article examines marital residence and sibling coresidence among horticulturalists in the South American lowlands. The authors reject a hypothesis that patrilocality is the defining trait of Amazonian tropical forest culture. Results on horticulturalists are compared with findings on hunter-gatherers: horticulturalists tend to be more uxorilocal. Empirical analysis also suggests that women tend to live with more kin later in life, and in large villages headmen live with more kin than nonheadmen.

This article uses factor analysis to identify the key variables underlying the many cross-cultural associations reported by Textor (1967). Twelve factors are identified.