Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Department of Anthropology, University College London, London, UK.
Nat Hum Behav. 2019 Nov;3(11):1154-1163. doi: 10.1038/s41562-019-0679-2. Epub 2019 Aug 12.
Human children are frequently cared for by non-parental caregivers (alloparents), yet few studies have conducted systematic alternative hypothesis tests of why alloparents help. Here we explore whether predictions from kin selection, reciprocity, learning-to-mother and costly signalling hypotheses explain non-parental childcare among Agta hunter-gatherers from the Philippines. To test these hypotheses, we used high-resolution proximity data from 1,701 child-alloparent dyads. Our results indicated that reciprocity and relatedness were positively associated with the number of interactions with a child (our proxy for childcare). Need appeared more influential in close kin, suggesting indirect benefits, while reciprocity proved to be a stronger influence in non-kin, pointing to direct benefits. However, despite shared genes, close and distant kin interactions were also contingent on reciprocity. Compared with other apes, humans are unique in rapidly producing energetically demanding offspring. Our results suggest that the support that mothers require is met through support based on kinship and reciprocity.
人类儿童经常由非亲生照顾者（养父母）照顾，但很少有研究对为什么养父母会提供帮助进行系统的替代假设检验。在这里，我们探讨了亲缘选择、互惠、母性学习和昂贵信号假说是否可以解释菲律宾阿塔加狩猎采集者的非亲生育儿现象。为了检验这些假说，我们使用了来自 1701 名儿童-养父母对偶的高分辨率接近数据。我们的结果表明，互惠和亲缘关系与与儿童的互动次数（我们的儿童保育代理）呈正相关。需要在近亲中更有影响力，表明存在间接利益，而互惠在非亲属中证明是更强大的影响，指向直接利益。然而，尽管有共同的基因，近亲和远亲的互动也取决于互惠。与其他猿类相比，人类在快速生育能量需求高的后代方面是独一无二的。我们的研究结果表明，母亲所需的支持是通过基于亲属关系和互惠的支持来满足的。
