Evolutionary anthropologists have long emphasized the puzzle of short inter-birth intervals, extended childhoods, and long post-reproductive lives of humans, in particular the problem it poses for raising children. While there is agreement that mothers receive assistance from kin to offset the high costs of raising children, opinion is equivocal as to which kin help and to what extent they help. Here the authors review 45 studies from historical and contemporary natural fertility populations to assess the effects of various types of kin on child survival rates.

By better understanding the factors influencing adult height in modern populations, the authors hope to generate a testable hypothesis to determine the factors affecting body size during hominin evolution. The authors employ an exploratory linear regression model to test the effects of mortality, environment, and subsistence strategy on adult height among traditional small scale human societies. They found that mortality rates were the most significant predictor of adult height and that people living in savanna environments are consistently taller.

In this article Hames addresses the long-standing disagreements between evolutionary theories regarding human warfare (more specifically between Rousseauian and Hobbesian frameworks). This study posits that while most current and previous research focuses on the discrepancies between the frequency and intensity with which warfare takes place between hunter-gatherer and large-scale societies, the ability for societies to live in peace with their neighbors despite the possibility for warfare, is the most important evolutionary trait. Coexisting peacefully is what distinguishes human socially and politically from chimpanzees whereas warfare itself is a more primitive trait humans share with previous ancestors. Hames concludes that going forward, use of phylogenetic methods to control for common ancestry, and use of archaeological data would lead to new and more comprehensive findings. Although largely a review of principal warfare literature, Hames does present an original statistical finding on adult violence mortality which is reported below.

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.

Researchers looked at four different demographic scenarios (altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes) and their possible effects on the rapid population growth of contemporary human foragers and steady population decline of chimpanzees. They evaluated these variables and the various conditions that would favor a more sustainable zero population growth (ZPG) among 10 small-scale subsistence human populations (Agta, Ache, Hadza, Hiwi, Ju/’hoansi, Gainj, Tsimane, Yanomamo, Northern Territory Aborigines, and Herero) and five wild chimpanzee groups (Gombe, Kanyawara, Mahale, Ngogo, and Taï). The results state that the most effective modifications towards ZPG would include a combination of more than one of the four demographic scenarios tested, with the most realistic solution including both vital rate alteration and an increase in catastrophes.

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.

Previous research into the origins of human violence and warfare has oftentimes been inconclusive and controversial. This paper examines two alternative theories as to the evolution of human violence using archaeological records on sharp force trauma (SFT) and blunt force trauma (BFT). The study is limited to 13 different California ethnolinguistic groups. Researchers find that violence is not predicted by sociopolitical complexity, but rather by environmental productivity. This supports the idea that in contexts of resource scarcity, the perceived benefits to engage in lethal aggression may outweigh perceived costs.

This article seeks to reevaluate the widespread assumption that hunter-gatherers lack the longevity that people in the modern, industrialized world enjoy. Through modeling life expectancy, mortality, and other demographic trends among extant hunter-gatherer, gatherer-horticulturalists, and horticulturalists societies they are able to challenge this belief. The authors conclude that longevity is a "novel feature of Homo sapiens" and that seven decades seems to be the natural lifespan of a human.

This article draws from anthropology, psychology, and history to gain insight into the causes of large-scale psychological variation among humans. The authors of this study are mainly concerned with the way that weak kinship structures induced by policies of the Western Church in Europe may have resulted in the modern "WEIRD" (an acronym for "Western, Educated, Industrialized, Rich, and Democratic") psychological profiles in that same region. By correlating the amount of contact with the Western Church, rates of cross-cousin marriage (as an element of kin tightness), and degrees of individualism (as an element of WEIRD psychology), the authors are able to find support for this theory.

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.