Can physiological variation in human populations be attributed to environmental variables? Arguing for the importance of phylogenetic comparative methods, the authors present the results of previous research by Holden & Mace (1997) on lactose intolerance as well as introduce new research on sex ratio at birth. The authors suggest that global variance in sex ratio at birth is an adapted response to the physiological costs of giving birth to boys in high fertility populations.

The researchers examine associations between male status and various measures of reproductive success among foraging/non-foraging, and monogamous/polygynous societies in order to test the "egalitarian hypothesis" which predicts lower status effects in hunter-gatherer groups. Contrary to this hypothesis, they find that male social status is equally significantly associated with reproductive success in foraging and nonforaging societies. Additional support is found for the "mating effort" hypothesis, which predicts that male reproductive success will be more associated with fertility than offspring mortality in polygynous societies, leading the authors to make various suggestions regarding the evolutionary mechanisms at play.

Textor summarizes cross-cultural findings on polygyny pertaining to cultural, environmental, psychological, and social phenomena.

This study attempted to replicate earlier findings regarding population structure and teen pregnancy rates. Findings support the previous predictions that sex ratio, economic development, and latitude are all inversely related to teen birth rates.

This article discusses the variation in sex ratios at birth among human populations and the possible explanations for this variation. One possible explanation is the timing of intercourse and its relationship to the frequency of intercourse, which can affect the timing of conception. The article presents evidence that the male/female sex ratios of 148 countries declined with total fertility rates and polygyny intensity and increased with contraception use in correlational analysis. These results were independent of mother's age and level of economic development. The predictive effect of polygyny and contraception disappeared when total fertility was added to the equation. The article also considers other possible explanations for the variation in sex ratios, such as genetics, hormones, nutrition, and social factors.

This study investigates the relationship between historical utilization of the plow and modern sex ratios. The authors argue that in societies without the plow subsistence is generally egalitarian with both men and women contributing. However, the use of the plow requires more physical strength which, they argue, leads to a preference for boys and, thus, men. Therefore, in cultures that use the plow, this is reflected in male-biased sex ratios which are negotiated by way of practices like sex-selective abortions, infanticide, and/or differential access to resources based on sex.

This article is a quantitative analysis of 592 participants from 8 societies. The study examines a number of theories about what predicts moralistic religions, including life history theory. Findings suggest that there is no evident relationship between these life history predictions and the religious beliefs regarding moralism.

This study tests competing theories about whether it is men, women, or parents who benefit most from restricting female premarital sex (FPS) in a global sample of 128 non-industrial societies. The study found support for the idea that multiple parties benefit from restrictions on FPS -- specifically FPS is more restricted in societies intolerant of extramarital sex and where men transfer property to their children (male control), as well as where marriages are arranged by parents (parental control). They also found that major predictors of FPS appear to be paternity uncertainty and parent-offspring conflict. Furthermore, the study found that multiple factors such as social roles, rather than stereotyped sex roles, are a more useful approach in understanding FPS restrictions and these restrictions.

This article explores how the evolutionary psychological perspective explains cultural universals and variations. This framework is then used to test whether wealth affects parents' preferences of sons or daughters on an individual and national level. Results suggest that wealthier individuals and wealthier nations prefer sons to daughters.

There is disagreement between existing theories on the relationship between leisure time and cultural complexity. This study tests Chick's (1986) hypothesis that simple and complex societies have more free time than those of moderate complexity. The relationship between cultural complexity and the economic productivity of children is also examined.