Small-scale human societies range from foraging bands with a strong egalitarian ethos to more economically stratified agrarian and pastoral societies. We explain this variation in inequality using a dynamic model in which a population's long-run steady-state level of inequality depends on the extent to which its most important forms of wealth are transmitted within families across generations. We estimate the degree of intergenerational transmission of three different types of wealth (material, embodied, and relational), as well as the extent of wealth inequality in 21 historical and contemporary populations. We show that intergenerational transmission of wealth and wealth inequality are substantial among pastoral and small-scale agricultural societies (on a par with or even exceeding the most unequal modern industrial economies) but are limited among horticultural and foraging peoples (equivalent to the most egalitarian of modern industrial populations). Differences in the technology by which a people derive their livelihood and in the institutions and norms making up the economic system jointly contribute to this pattern.
See ScienceDaily for a summary. Two immediate thoughts come to mind: 1) Many people have long suggested in many ways "advanced" industrial nations are shifting back toward the values which are more common among hunter-gatherers. "Traditional" values the norm among pre-modern agriculturists may be a peculiar interlude, when native human intuitions and the range of personal choice were constrained by powerful lineages which monopolized wealth. 2) I wonder if the differences in wealth & inequality track reproductive variance. Specifically, if the range of relative fitness is higher in societies with more inequality. This could have an evolutionary impact, one can posit that more variance in fitness means more rapid change in phenotypic values. Genghis Khan wouldn't have been possible among hunter-gatherers.