This article examines possible environmental predictors of ethnic diversity around the world. Results suggest that global ethnic diversity is associated with latitude, habitat diversity, pathogen stress, and climate.

This article examines possible environmental predictors of ethnic diversity around the world. Results suggest that global ethnic diversity is associated with latitude, habitat diversity, pathogen stress, and climate.

Researchers investigated further into why and how humans speak so many languages across the globe, and why they are spread out unevenly. Using two different path analyses, a Stationary Path analysis and a GWPath, researchers tested the effect of eight different factors on language diversity. Out of the eight variables (river density, topographic complexity, ecoregion richness, temperature and precipitation constancy, climate change velocity, population density, and carrying capacity with group size limits), population density, carrying capacity with group size limit, and ecoregion richness had the strongest direct effects. Overall, the study revealed the role of multiple different mechanisms in shaping language richness patterns. The GWPath showed that not only does the most important predictor of language diversity vary over space, but predictors can also vary in the direction of their effects in different regions. They conclude that there is no universal predictor of language richness.

This article investigates the adoption of agriculture. The author tests three possible predictors: environmental richness, population density, and division of labor by gender. Minimal support is found for these variables, and the author proposes two alternative explanations, based on diminishing returns in food production and balancing the food portfolio.

This article explores the relationships between habitat and social organization among humans and other species. Diet, technology, group size, home range, mobility, kinship, marital residence, sexual division of labor, mating system, central places, food sharing, and egalitarianism are all considered.

The authors test the relationship between ethnolinguistic area and various environmental variables in a cross-cultural sample of hunter-gatherer, pastoral, and agricultural subsistence groups in order to evaluate various hypotheses surrounding the geographic and ecological origins of cultural diversity. They propose that societies which adopted agriculture at the beginning of the Holocene were less directly affected by climate which, combined with the effect of increasing political and cultural complexity, allowed coordination and homogenization of ethnolinguistic groups over a broader swathe of territory.

This paper builds off previous research into the effect of population size and resource risk on complexity of subsistence technology by investigating the relationship between these independent variables and total number of material items and techniques used by various western North American hunter-gatherer groups. This tally of total technological complexity is found to be insignificantly related to population size or residential mobility; however, there is a significant correlation in the expected direction between technological complexity and one measure of resource risk (mean annual temperature during driest month). Tying this finding to previous analyses of subsistence technologies, the authors theorize that environmental risk is a pervasive driver of technological ingenuity and cultural evolution.

Inter-group variation is greater in humans than in any other animal, and scholars continue to debate the cause of this diversity. Two competing explanatory models of human variation emphasize either (1) ecological differences and "evoked" culture or (2) population-level effects of cultural transmission. The former emphasizes mechanisms that operate within a single generation, while the latter emphasizes cumulative cultural history operating over many generations. To test these competing models, the authors measured the relative power of ecological variables as compared to culture history to predict behavioral variation in 172 western North American tribes. Culture history is subdivided into culture phylogeny (based on language phylogeny) and spatial distance.

This article explores the relationships between habitat and social organization among humans and other species. Diet, technology, group size, home range, mobility, kinship, marital residence, sexual division of labor, mating system, central places, food sharing, and egalitarianism are all considered.

This article tests a myriad of factors that may have contributed to the adoption of monogamy in preindustrial societies. Results indicate that monogamy is not imposed by elites; rather, it is a strategy often chosen by women who can see no advantage to increasing the size or economic productivity of their households with more wives. The authors also assert that monogamy is generally adopted through cultural diffusion. Low pathogen stress, low risk of famine, and low endemic violence are also correlated with monogamy.