Data from: Strong social relationships are associated with decreased longevity in a facultatively social mammal

Humans in strong social relationships are more likely to live longer because social relationships may buffer stressors and thus have protective effects. However, a shortcoming of human studies is that they often rely on self-reporting of these relationships. By contrast, observational studies of nonhuman animals permit detailed analyses of the specific nature of social relationships. Thus, discoveries that some social animals live longer and healthier lives if they are involved in social grooming, forage together, or have more affiliative associates emphasizes the potential importance of social relationships on health and longevity. Previous studies have focused on the impact of social metrics on longevity in obligately social species. However, if sociality indeed has a key role in longevity, we might expect that affiliative relationships should also influence longevity in less social species. We focused on socially flexible yellow-bellied marmots (Marmota flaviventer) and asked whether female longevity covaries with the specific nature of social relationships. We quantified social relationships with social network statistics that were based on affiliative interactions, and then estimated the correlation between longevity and sociality using bivariate models. We found a significant negative phenotypic correlation between affiliative social relationship strength and longevity; marmots with greater degree, closeness, and those with a greater negative average shortest path length died at younger ages. We conclude that sociality plays an important role in longevity, but how it does so may depend on whether a species is obligately or facultatively social.

拥有牢固社会关系的人类更易长寿，这是由于社会关系能够缓冲压力源，进而发挥保护作用。不过，针对人类的研究存在一项局限：这类研究大多依赖于个体对自身社会关系的自我报告。与之相对，对非人类动物的观察研究可实现对社会关系具体本质的精细化分析。已有研究表明，部分社会性动物若参与社交理毛（social grooming）、共同觅食，或拥有更多亲和性同伴，便能拥有更长寿命与更佳健康状态，这一发现凸显了社会关系对健康与寿命的潜在重要性。

既往研究多聚焦于专性社会性（obligately social）物种的社会指标对寿命的影响。但若社会性确实对寿命有关键作用，那么我们可以推测，亲和性关系同样会影响低社会性物种的寿命。本研究以社会灵活性较强的黄腹旱獭（Marmota flaviventer）为对象，探究雌性个体的寿命是否与社会关系的具体特征存在关联。我们基于亲和性互动（affiliative interactions）计算社交网络统计指标以量化社会关系，并通过双变量模型（bivariate models）估算寿命与社会性之间的相关性。研究发现，亲和性社会关系强度与寿命之间存在显著的负表型相关性：度中心性更高、接近中心性更强，以及平均最短路径长度负值更大的旱獭，其死亡年龄更早。综上，社会性对寿命具有重要作用，但其具体作用机制可能取决于物种属于专性社会性还是兼性社会性（facultatively social）。