Glowacki Luke, Wrangham Richard
Department of Human Evolutionary Biology, Harvard University, Peabody Museum, Cambridge, MA 02138
Department of Human Evolutionary Biology, Harvard University, Peabody Museum, Cambridge, MA 02138.
Proc Natl Acad Sci U S A. 2015 Jan 13;112(2):348-53. doi: 10.1073/pnas.1412287112. Epub 2014 Dec 29.
Intergroup conflict is a persistent feature of many human societies yet little is known about why individuals participate when doing so imposes a mortality risk. To evaluate whether participation in warfare is associated with reproductive benefits, we present data on participation in small-scale livestock raids among the Nyangatom, a group of nomadic pastoralists in East Africa. Nyangatom marriages require the exchange of a significant amount of bridewealth in the form of livestock. Raids are usually intended to capture livestock, which raises the question of whether and how these livestock are converted into reproductive opportunities. Over the short term, raiders do not have a greater number of wives or children than nonraiders. However, elders who were identified as prolific raiders in their youth have more wives and children than other elders. Raiders were not more likely to come from families with fewer older maternal sisters or a greater number of older maternal brothers. Our results suggest that in this cultural context raiding provides opportunities for increased reproductive success over the lifetime.
群体间冲突是许多人类社会长期存在的特征，但对于个体在参与会带来死亡风险的冲突时为何仍选择参与，我们却知之甚少。为了评估参与战争是否与生殖益处相关，我们展示了关于东非游牧牧民群体尼扬加托人参与小规模牲畜掠夺的数据。尼扬加托人的婚姻需要以牲畜的形式交换大量彩礼。掠夺通常旨在捕获牲畜，这就引发了这些牲畜是否以及如何转化为生殖机会的问题。短期内，参与掠夺者的妻子或孩子数量并不比未参与掠夺者多。然而，年轻时被认定为多产掠夺者的年长者比其他年长者拥有更多的妻子和孩子。掠夺者并非更有可能来自年长姐妹较少或年长兄弟较多的家庭。我们的研究结果表明，在这种文化背景下，掠夺为一生中提高生殖成功率提供了机会。
