The researchers utilize a GIS approach in order to examine the relationship between global linguistic distribution and various cultural and environmental factors. The resulting positive association between political complexity and both latitude and language range leads the researchers to propose that large, politically complex entities exert a homogenizing pressure on language. However, the causal link may also be in the other direction, with possession of common language facilitating the creation of more complex political institutions.

The 'obstetrical dilemma' postulates that human females evolved a pelvis shape that was a compromise between the needs of bipedal locomotion and the need for a wider pelvic opening. The implication is that the female pelvis should be similar across the world. Researchers examine the size and shape of the birth canal of female individuals in the Goldman and Human Origin datasets. Contrary to the 'obstetrical dilemma,' the findings reveal that there is indeed significant geographical variation in size and shape of the female birth canal. Neutral evolutionary processes, particularly genetic drift, were suggested to be influential in female canal shape whereas the predicted effects of climate on canal diversity were only minimal.

Using a representative sample of 339 hunter-gatherer societies, researchers examine the relationship between hunter-gatherer use of space, size of population and supply of resources to see if they are similar to other organisms. By combining all factors into a single model, the authors claim to explain 86% of the variation in home range. Hunters have greater resource distribution than gatherers but both more so than aquatic foragers. Lastly, terrestrial foragers have more extensive home ranges than aquatic foragers.

Dietary variation has been implicated in population-level heath outcomes such as adult height and infant health. Here the author investigates these relationships in a sample of 118 nonindustrial societies, providing a comparative and quantitative assessment of nutrition and health cross-culturally.

The authors use a comparative ethnoarchaeological model that seeks to test the applicability of Dynamical Systems Theory to modeling subsistence variation (namely the foraging-farming transition). The authors utilize the concepts of "attractors," which tend to stabilize a system, and "repellors," which tend to be destabilizing forces. Authors hope that this multidimensional approach, which assumes that several "controlling" variables disproportionately affect change within subsistence systems, will adequately model the nonlinearity and heterogeneity seen in the emergences of (and variations within) human subsistence systems throughout human history. Their model and premises regarding disproportionally-controlling variables appear to be supported.

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 study seeks to better understand different forms of leadership across non-WEIRD (Western, Educated, Industrialized, Rich, and Democratic) societies, and tests evolutionary theories regarding the qualities of leaders, their functions, and the costs and benefits they incur and provide as a part of their leadership. The authors assess the various aspects of leaders and leadership by coding 109 dimensions of leadership as represented in eHRAF World Cultures, using the Probability Sample Files, comprised on 60 cultures. By assessing the prevalence of each of these dimensions in the various cultures under consideration, the authors were able to ascertain some largely universal characteristics of leaders: that they 1) were judged intelligent and knowledgeable; 2) resolved conflicts; and 3) received material and social benefits. They also found that other dimensions varied by considerably group context (e.g., kin group leaders tended to be older), subsistence strategy (e.g., hunter-gatherer leaders tend to lack coercive authority), and gender (e.g., female leaders are more associated with family contexts). Further analyses showed that followers and leaders both benefited from leadership, and that shamans constitute a new brand of leader that both utilizes prestige and dominance in order to effectively rule.

Using the compiled database "Seshat: Global History Databank," researchers sampled 30 societies from 10 distinct regions of the world, testing 51 variables that were condensed into 9 "complex characteristic" variables. Researchers tested for correlates in how societies evolve structurally. Utilizing principal component analysis it was demonstrated that the complex characteristic variables were strongly associated, leading to theorization of structural and social evolution predictability.

This study tests the validity of two previous diachronic studies examining the relationship between subsistence strategy and sexual dimorphism of stature with synchronic data. The authors find that neither hypothesis is valid.

This article examines the relationship between sexual dimorphism of stature and latitude; data support the association. The authors also find support for an association between latitude and human marriage systems, a variable proposed by Alexander (1979) to explain variation in sexual dimorphism of stature. When societies are categorized by latitude, the relationships between marriage systems and sexual dimorphism do not reach significance. Overall the authors emphasize the influence of environmental adaptation on sexual dimorphism rather than an explanation solely focused on male-male competition.