Background: Human inbreeding is a sociobiological puzzle. Despite widespread knowledge of its potential for genetic disorders, human consanguinity remains surprisingly common. The current reasons explaining its continued persistence in today’s modern world have major shortcomings. Summary: We propose that the Neolithic Agrarian revolution modified the structure of populations. It increased competition for the limited resources in which a larger group had better chances of survival. As a result, small, drifting, socially open bands of hunter-gatherers were transformed into bigger, less mobile, and more powerful kinship groups (tribes). In this transformation, a central role was played by human trust – an aspect of human altruism which is a universal sociobiological principle of behavior. Altruism (and trust) is an essential premise of social contracts such as economic cooperation, marriage arrangement, and creation of alliances between people. In kinship groups, human trust is limited to kin, so tribes remain small, economically poor, and consanguineous due to lack of nonkin mates. The expanding of trust from kin to that of nonbiological relatives increases the size of human groups, fosters economic wealth, and decreases the rate of consanguinity. Key Messages: The lack of nonkin altruism leads to: (a) poverty (due to poor economic cooperation with nonkin), (b) maintaining small group size, and (c) inbreeding.
Public Health Genomics

中文翻译：

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利他主义作为人类血缘关系的解释


背景：人类近亲繁殖是一个社会生物学难题。尽管人们普遍知道近亲结婚可能导致遗传性疾病，但人类近亲结婚仍然令人惊讶地普遍。目前解释其在当今现代世界持续存在的原因存在重大缺陷。摘要：我们认为新石器时代的土地革命​​改变了人口结构。它加剧了对有限资源的竞争，而更大的群体有更好的生存机会。结果，小型的、流动的、社会开放的狩猎采集者群体转变为更大、流动性更弱、更强大的亲属群体（部落）。在这一转变中，人类信任发挥了核心作用——人类利他主义的一个方面，是普遍的社会生物学行为原则。利他主义（和信任）是经济合作、婚姻安排和人与人之间建立联盟等社会契约的重要前提。在亲属群体中，人类的信任仅限于亲属，因此部落仍然很小，经济贫困，并且由于缺乏非亲属伴侣而保持近亲关系。信任从亲属扩大到非生物亲属，扩大了人类群体的规模，促进了经济财富，并降低了近亲率。关键信息：缺乏非亲属利他主义会导致：(a) 贫困（由于与非亲属的经济合作不力），(b) 维持小群体规模，以及 (c) 近亲繁殖。
 公共卫生基因组学