Old chimp friends As humans age, we prioritize established positive friendships over the new, but risky, socializing we do when we are young. It has been hypothesized that this shift may come as our own sense of mortality kicks in. Rosati et al. analyzed a rare, long-term dataset on social bonds among male chimpanzees and found a very similar focus on old and positive friendships (see the Perspective by Silk). Though there is evidence of some sense of time among nonhuman animals, it seems unlikely that they have the same impending sense of mortality that we experience; thus, these results suggest that a different, and deeper, mechanism may be at play. Science, this issue p. 473; see also p. 403 Male chimps focus on old friends as they age. Humans prioritize close, positive relationships during aging, and socioemotional selectivity theory proposes that this shift causally depends on capacities for thinking about personal future time horizons. To examine this theory, we tested for key elements of human social aging in longitudinal data on wild chimpanzees. Aging male chimpanzees have more mutual friendships characterized by high, equitable investment, whereas younger males have more one-sided relationships. Older males are more likely to be alone, but they also socialize more with important social partners. Further, males show a relative shift from more agonistic interactions to more positive, affiliative interactions over their life span. Our findings indicate that social selectivity can emerge in the absence of complex future-oriented cognition, and they provide an evolutionary context for patterns of social aging in humans.

中文翻译：

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老龄野生黑猩猩的社会选择性

老黑猩猩朋友随着人类年龄的增长，我们优先考虑建立积极的友谊，而不是我们年轻时进行的新的但有风险的社交活动。据推测，这种转变可能会随着我们自己的死亡意识开始而出现。Rosati 等人。分析了一个关于雄性黑猩猩之间社会联系的罕见的长期数据集，发现对旧友谊和积极友谊的关注非常相似（参见 Silk 的 Perspective）。尽管有证据表明非人类动物具有某种时间感，但它们似乎不太可能像我们所经历的那样具有即将到来的死亡感；因此，这些结果表明可能存在一种不同的、更深层次的机制。科学，本期第 3 页。473; 另见第 403 雄性黑猩猩随着年龄的增长会关注老朋友。人类在衰老过程中优先考虑亲密、积极的关系，社会情感选择性理论认为，这种转变在因果上取决于思考个人未来时间范围的能力。为了检验这一理论，我们在野生黑猩猩的纵向数据中测试了人类社会老化的关键因素。年长的雄性黑猩猩有更多的相互友谊，其特点是高额、公平的投资，而年轻的雄性黑猩猩则有更多片面的关系。年长的男性更有可能独处，但他们也更多地与重要的社会伙伴交往。此外，男性在其一生中表现出从更激烈的互动到更积极、更亲近的互动的相对转变。我们的研究结果表明，社会选择性可以在没有复杂的面向未来的认知的情况下出现，它们为人类社会老龄化模式提供了进化背景。