Friday, September 30, 2016

Pre-Industrial Societies Reward High Status Men With More Children

From the hunter-gatherer era and on into societies based on herding and farming, high social status men have significantly more children than low social status men. Then, in the industrial era, that relationship was inverted. That is the conclusion of a new meta-analysis of 33 pre-industrial societies.

I've seen a study along the same lines out of a University of Michigan scholar a decade or two ago, that looked at historical and legendary history documents to show the gradually decreasing number of mates and children of ultra high status men from the Bronze Age through the present, with significant changes continuing even from the Victorian era to the 20th century. The drivers of this change aren't entirely clear.

The study and its abstract are as follows:
Social status motivates much of human behavior. However, status may have been a relatively weak target of selection for much of human evolution if ancestral foragers tended to be more egalitarian. We test the “egalitarianism hypothesis” that status has a significantly smaller effect on reproductive success (RS) in foragers compared with nonforagers. We also test between alternative male reproductive strategies, in particular whether reproductive benefits of status are due to lower offspring mortality (parental investment) or increased fertility (mating effort). We performed a phylogenetic multilevel metaanalysis of 288 statistical associations between measures of male status (physical formidability, hunting ability, material wealth, political influence) and RS (mating success, wife quality, fertility, offspring mortality, and number of surviving offspring) from 46 studies in 33 nonindustrial societies. We found a significant overall effect of status on RS (r = 0.19), though this effect was significantly lower than for nonhuman primates (r = 0.80). There was substantial variation due to marriage system and measure of RS, in particular status associated with offspring mortality only in polygynous societies (r = −0.08), and with wife quality only in monogamous societies (r = 0.15). However, the effects of status on RS did not differ significantly by status measure or subsistence type: foraging, horticulture, pastoralism, and agriculture. These results suggest that traits that facilitate status acquisition were not subject to substantially greater selection with domestication of plants and animals, and are part of reproductive strategies that enhance fertility more than offspring well-being.
Christopher R. von Rueden, Adrian V. Jaeggi. "Men’s status and reproductive success in 33 nonindustrial societies: Effects of subsistence, marriage system, and reproductive strategy." 113 (39) Proceedings of the National Academy of Sciences 10824 (2016).

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