von Rueden Christopher R, Jaeggi Adrian V
Jepson School of Leadership Studies, University of Richmond, Richmond, VA 23173;
Department of Anthropology, Emory University, Atlanta, GA 30316.
Proc Natl Acad Sci U S A. 2016 Sep 27;113(39):10824-9. doi: 10.1073/pnas.1606800113. Epub 2016 Sep 6.
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.
社会地位激发了人类的大部分行为。然而，如果祖先觅食者倾向于更加平等，那么在人类进化的大部分时间里，地位可能一直是一个相对较弱的选择目标。我们检验“平等主义假说”，即与非觅食者相比，地位对觅食者生殖成功率（RS）的影响要小得多。我们还在不同的男性生殖策略之间进行检验，特别是地位的生殖益处是否源于较低的后代死亡率（亲代投资）或较高的生育率（交配努力）。我们对来自33个非工业社会的46项研究中男性地位（身体威慑力、狩猎能力、物质财富、政治影响力）与RS（交配成功率、妻子质量、生育率、后代死亡率和存活后代数量）测量之间的288个统计关联进行了系统发育多层次荟萃分析。我们发现地位对RS有显著的总体影响（r = 0.19），尽管这种影响明显低于非人类灵长类动物（r = 0.80）。由于婚姻制度和RS测量存在很大差异，特别是在一夫多妻制社会中，地位仅与后代死亡率相关（r = -0.08），而在一夫一妻制社会中，地位仅与妻子质量相关（r = 0.15）。然而，地位对RS的影响在地位测量或生存方式（觅食、园艺、畜牧和农业）方面没有显著差异。这些结果表明，促进地位获得的特征在动植物驯化过程中并没有受到更大的选择，并且是生殖策略的一部分，这些策略更多地提高了生育率而非后代的福祉。
