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.

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.

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.

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 seeks to understand male-female bonding by testing the relationship between male contribution to subsistence (a proxy for male provisioning) and female reproductive success in foraging societies. Analysis supports a positive association.

This article seeks to understand male-female bonding by testing the relationship between male contribution to subsistence (a proxy for male provisioning) and female reproductive success in foraging societies. Analysis supports a positive association.

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 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 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.