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 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 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.

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.

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.

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.

The authors examine degree of intensiveness (kin-relatedness) among foraging and agropastoralist societies, predicting that hunter-gatherers will pursue more extensive kinship networks in order to maximize residential options in the case of unpredictability or uneven geographic distribution of food resources. Support is found for the hypothesis, and it is suggested that while extensive fission-fusion dynamics are beneficial in foraging systems, the increase in cooperation in large-scale agricultural settlements is aided by norms which encourage kin marriage and relatedness.

This chapter attempts to explain why the number, importance, and duration of food and sex taboos during pregnancy vary cross-culturally. The author hypothesizes that differences in child socialization will be associated with differences in food taboos, and differences in sexual behavior and sanctions will be associated with sex taboos. Results support the hypotheses.

Researchers examine marriage patterns of 186 societies from the Standard Cross-Cultural Sample (SCCS). The eleven predictor variables are pathogen stress, arranged female marriages, population density, father roles during infancy, temperature, social stratification, wealth inequality, internal warfare, assault frequency, female agricultural contribution, and sex ratio. The two outcome variables measuring polygyny are cultural rules constraining polygyny and the percentage of married men who are polygynous. Controlling on phylogeny using a global supertree of the languages, analysis of marriage patterns reveals that assault frequency and pathogen stress are the strongest predictors of polygyny. These findings offer additional support for the theories of harem-defense polygyny and male genetic quality.

This article tests the effect of environmental risk on parental investment, differentiating between maternal and paternal care. Results indicate that the saturation point of parental investment may be a function of environmental risk, as parental care experiences diminishing returns due to extrinsic risks.