Department of Anthropology, University of California, Los Angeles, CA 90024, USA.
Proc Natl Acad Sci U S A. 2013 Sep 3;110(36):14586-91. doi: 10.1073/pnas.1221217110. Epub 2013 Aug 19.
Humans are an exceptionally cooperative species, but there is substantial variation in the extent of cooperation across societies. Understanding the sources of this variability may provide insights about the forces that sustain cooperation. We examined the ontogeny of prosocial behavior by studying 326 children 3-14 y of age and 120 adults from six societies (age distributions varied across societies). These six societies span a wide range of extant human variation in culture, geography, and subsistence strategies, including foragers, herders, horticulturalists, and urban dwellers across the Americas, Oceania, and Africa. When delivering benefits to others was personally costly, rates of prosocial behavior dropped across all six societies as children approached middle childhood and then rates of prosociality diverged as children tracked toward the behavior of adults in their own societies. When prosocial acts did not require personal sacrifice, prosocial responses increased steadily as children matured with little variation in behavior across societies. Our results are consistent with theories emphasizing the importance of acquired cultural norms in shaping costly forms of cooperation and creating cross-cultural diversity.
人类是一种非常善于合作的物种，但不同社会之间的合作程度存在很大差异。了解这种可变性的来源可能有助于我们了解维持合作的力量。我们通过研究六个社会中的 326 名 3-14 岁的儿童和 120 名成年人，研究了亲社会行为的个体发生。这六个社会跨越了人类在文化、地理和生存策略方面的广泛现存差异，包括来自美洲、大洋洲和非洲的觅食者、牧民、园艺家和城市居民。当给他人带来好处会给自己带来个人成本时，随着儿童接近中年，所有六个社会的亲社会行为率都会下降，然后随着儿童跟踪自己社会中成年人的行为，亲社会行为率会出现分歧。当亲社会行为不需要个人牺牲时，亲社会反应会随着儿童的成熟而稳步增加，不同社会之间的行为变化很小。我们的研究结果与强调后天习得的文化规范在塑造有代价的合作形式和创造跨文化多样性方面的重要性的理论一致。
