Previous studies have yielded contradictory results on the relationship between population size and cultural evolution. Focusing on tool complexity these authors introduce the risk of resource failure as a possible confounding variable. They conclude that population does not predict tool kit complexity when controlling on other factors. There were significant correlations between tool kit complexity and some of the resource measures.

Seeking to resolve contradictions between previous studies, these authors conduct empirical analysis on the relationship between population size and cultural evolution. Results indicate that population size influences toolkit richness and complexity, even when proxies for risk of resource failure are introduced in the regression model. Authors speculate that the association is weaker for hunter-gatherers because those societies are more affected by risk of resource failure and have institutions that facilitate cultural evolution despite smaller population size. There also may be a threshold effect in the influence of population size on toolkit structure.

This study tests four hypotheses that propose potential environmental and social predictors of toolkit size and complexity among hunter-gatherers. Hypotheses predicting relationships between population size, residential mobility, type of food resources and toolkit structure are not supported. Risk of resource failure is the only variable that is significantly associated with toolkit structure.

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.

Prior research by Oswalt (1973, 1976) and Torrence (1983, 2001) has suggested that risk of resource failure is a significant predictor of toolkit complexity and diversity among hunter-gatherers. In this paper, the same relationship is tested among small-scale herding and farming groups. However, no significant correlation is discovered between any measure of resource risk and any measure of toolkit complexity. The researchers suggest that this absence may be the result of greater reliance on non-technological diversification methods among farmers (i.e. spatial diversification, mixed farming, intercropping), or of other unaccounted-for sources of risk (i.e. intergroup raiding and warfare).

The researchers test the relationship between toolkit complexity and diversity as defined by Oswalt (1973) and environmental and demographic variables. Neither population size nor risk of resource failure predict toolkit characteristics among all groups in the sample. However, population size is significantly positively correlated with toolkit diversity and complexity among food-producers, whereas environmental factors indicating risk of resource failure are significantly positively correlated among hunter-gatherers. This leads the researchers to suggest that food-producers' effectiveness at niche construction is a result of their large population size, which thus has a larger effect on toolkit composition than does environmental risk relative to hunter-gatherers.

It is suggested that the degree of political complexity is more strongly related to degree of social differentiation than to size and concentration of population.

This paper studies Pelto's (1962, 1968) operational definition for the tightness and looseness of societies in relation to child rearing practices. Results suggest that societies with a "tight" social structure will have child training practices that promote conformity and obedience and vice versa.

This article examines the different social risk-management strategies (SRMS) used by pastoralists to minimize their exposure to risks that may affect their livelihood. The authors identify a new type of SRMS, noninstitutionalized SRMS, to the two existing types, exchange networks and patron-client relations. A qualitative comparative analysis (QCA) is used to identify factors which explain the variation in SRMS: livelihood diversification, economic differentiation, political economy, risk exposure, and key economic animal.

The authors test the relationship between disease prevalence and three different personality traits, with the expectation that pathogen load will be negatively associated with degree of sociosexuality, extraversion, and openness to experience. This prediction is supported by all three tests, which they theorize is an example of cultural behaviors adapting to reduce vulnerability to environmental risks.