This article uses logistic regression analysis to examine pathogen stress and male mortality in warfare as predictors of nonsororal polygyny. Differences between state and non-state societies are observed. The authors also retest variables from White and Burton's 1988 study on causes of polygyny, finding only fraternal interest groups and absence of plow significant.

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 study explores ecological reasons that might explain why boys are mostly circumcised in tropical regions, particularly in Africa and the insular Pacific. The author postulates a long causal chain linking: 1) tropical climate to the growing of root and fruit crops; 2) the need to keep babies on mother's milk for as long as possible where the adult diet is lacking in protein; 3) a long post-partum sex taboo as a way to space births; 4) the practice of polygyny (and associated mother-child sleeping) in the face of a long sex taboo; 5) patrilocal residence; and 6) male initiation ceremonies which are believed to result from the combination of mother-child sleeping, the long poast-partum sex taboo and patrilocal residence.

This article focuses on the effect of environmental extremes and unpredictability on human behavior and reproductive strategies. Significant correlations were found between environmental extremes and unpredictability and several variables, including mobility, subsistence mode, and degree of polygyny.

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.

This article examines the relationship between pathogen stress and polygyny. Results indicate that there is a positive association between the two that is not confounded by geographic region, latitude, population density, male-male competition, or presence of brideprice. In particular, pathogen stress precicts higher levels of non-sororal polygyny and capturing women for wives or concubines.

This article tests several hypotheses related to the presence or absence of polygyny. Results suggest a negative relationship between polygyny and male provisioning, and positive relationships between polygyny and warfare, interpersonal aggression, and pathogen stress.

This paper supports Beatrice B. Whiting's (1965) sex-identity conflict hypothesis which suggests a relationship between males' early identification with their mothers and male violence. Authors find that, in addition to socialization aggression, frequency of homicide/assault is significantly related to father-infant sleeping distance, particularly when residence is not matrilocal and/or warfare is more than occasional.

This study tests three hypotheses on the evolution of the human pair-bond: male-provisioning, male mating competition, and the defense of offspring from other males. Findings indicate that male provisioning and mating competition are factors in the development of the pair-bond. Additional findings indicate that alloparentling, polygyny, and equal contribution to subsistence by each sex contribute to the security of the pair-bond.

This study retests the work by Ember, Ember and Low (2007) on male mortality and pathogen stress as predictors of nonsororal polygyny. The authors argue that the work of Ember, Ember, and Low is biased because it does not include a variable for cultural trait transmission. Restesting the original Ember, Ember and Low data, including a variable for cultural trait transmission, authors find that male mortality and pathogen stress loose their significance and cultural trait transmission is the only significant predictor of nonsororal polygyny.