Data from: Family network size and survival across the lifespan of female macaques

Two decades of research suggest social relationships have a common evolutionary basis in humans and other gregarious mammals. Critical to the support of this idea is growing evidence that mortality is influenced by social integration, but when these effects emerge and how long they last is mostly unknown. Here, we report in adult female macaques that the impact of number of close adult female relatives, a proxy for social integration, on survival is not experienced uniformly across the life course; prime-aged females with a greater number of relatives had better survival outcomes compared with prime-aged females with fewer relatives, whereas no such effect was found in older females. Group size and dominance rank did not influence this result. Older females were less frequent targets of aggression, suggesting enhanced experience navigating the social landscape may obviate the need for social relationships in old age. Only one study of humans has found age-based dependency in the association between social integration and survival. Using the largest dataset for any non-human animal to date, our study extends support for the idea that sociality promotes survival and suggests strategies employed across the life course change along with experience of the social world.

二十余年的研究表明，人类与其他群居哺乳动物（gregarious mammals）的社交关系拥有共同的进化基础。支撑这一观点的关键证据正不断积累：社交整合（social integration）会影响死亡率，但这类影响何时出现、持续多久，目前尚不明晰。本研究以成年雌性猕猴为对象，发现作为社交整合替代指标的成年雌性近亲数量对存活率的影响，并非贯穿整个生命历程且均匀一致：拥有更多近亲的壮年雌性猕猴，其存活率显著高于近亲数量较少的壮年个体，而老年雌性猕猴则未观察到此类效应。种群规模与支配等级（dominance rank）并未对该结果产生影响。老年雌性猕猴遭受攻击的频率更低，这表明随着社交场景应对经验的积累，老年个体或许不再需要依赖社交关系即可维持生存。目前仅有一项人类研究发现，社交整合与存活率之间的关联存在年龄依赖性。本研究使用了迄今规模最大的非人类动物数据集，进一步验证了社交行为有助于提升存活率这一观点，并表明个体在生命历程中采用的社交策略，会随着其社交经验的积累而发生改变。