This article presents a model of cultural evolution simulating the accumulation of tools in specialized and non-specialized populations under different demographic and environmental scenarios. The model predicts that the relationship between population size and repertoire size is nonlinear and can differ between non-specialized and specialized populations. For small population sizes, the non-specialized populations maintain knowledge better and therefore reach higher average repertoire sizes. In large populations, specialized populations can reach higher average repertoire sizes. This is because non-specialized population's total repertoire size is limited by the capacity of individuals to accumulate knowledge of different skills, while in specialized populations, each individual needs to know only a fraction of the population's repertoire. However, the model also predicts that specialized populations are more susceptible to information loss due to their subdivision of knowledge, and this can be amplified by demographic and environmental factors. The authors also use ethnographic data to analyze the relationship between population size and degree of craft specialization of societies, and how this may be influenced by ecological factors.

Scholars generally agree that, across languages, the relationship between particular sounds and the meaning of words is arbitrary. In this article the authors test this assumption, seeking patterned associations between sound and meaning in the basic vocabulary lists of a large, worldwide sample of languages.

This paper seeks to identify how different practices of food sharing are related to one another, and the degree to which societies in North and South America may share practices with one another. The authors attempt this by using ethnographic literature to break sharing activities down into their constituent, multi-stage parts, and then comparing the prevalence of these parts and their relationships to one another. The study finds that the presence or absence of a distributor in a sharing activity, and who that distributor is, has a significant effect on how sharing is carried out. On the other hand, linguistic relationships between groups seem to have little impact on their sharing practices, and geographic proximity between groups only seems to have a significant effect on sharing practices in North America.

Jared Diamond previously argued that the East-West orientation of Eurasia allowed for the spread of substantial cultural, political, technological, and military innovations, due to environmental homogeneity across the continent. The authors of this article test this theory through quantitative analyses. Their results suggest that ecology can indeed influence the potential for cultural transmission, consistent with Diamond's theory. However, the authors do not find support for Eurasia having lower environmental barriers to cultural transmission in comparison to other continents.