This study seeks to examine the influence that UV radiation and climate might have on gender inequality, and tests two extant theories on why gender inequality exists -- the life-history theory (aligned with climate) and the cognitive performance theory (aligned with UV radiation). The model with UV radiation as the main predictor fits the data on gender inequality the best, and pathogen prevalence and the ACP1*B allele were also found to be associated with gender inequality. The model was found to be robust across continents and ancestry. The study also highlights the need for further research to better understand the complex interplay of these factors in different cultures.

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.

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.

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 tests for a relationship between subsistence type and fertility using phylogenetic and statistical analyses. The authors find a clear relationship between dependence on agriculture and fertility among non-permanently settled groups.

This study provides the first tests of the relationships between population-level adolescent fertility rates and mortality risk at two different time points. The hypotheses are based in life-history theory, which predicts that human reproductive choices are shaped by mortality. The authors find that reproductive strategies are significantly predicted by both early (between ages 1-7) risks of mortality and current cues of mortality risk.

This article examines the relationship between HIV/AIDS and several parameters of a nation’s demography, including income, mortality, labor, fertility, and homicide rates. Associations were supported by statistical tests. Regional differences are considered; Europe and the Muslim area had lower level of women’s HIV/AIDS infection. Four cultural adaptations to combat STDs are discussed.

This article presents theory and hypothesis tests that suggest that the decline of women's contribution to intensive agriculture is related to increases in fertility and domestic work associated with cereal crops. Additionally, men in agricultural societies are less likely to invest time in hunting and warfare, so their contribution of agricultural labor relative to women's increases.

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.

What explains global variation in sex ratio at birth? To address this question, the authors present the results of their previous research on sex ratio at birth (2003), and additionally introduce new research on the correlations between sex ratio and marriage costs, such as a dowry or brideprice. Using a phylogenetic approach, the authors find that there is no correlation between sex ratio at birth and marriage payments. Analysis is restricted to the Old World.