Social integration and social status can substantially affect an individual's health and survival. One route through which this occurs is by altering immune function, which can be highly sensitive to changes in the social environment. However, we currently have limited understanding of how sociality influences markers of immunity in naturalistic populations where social dynamics can be fully realized. To address this gap, we asked if social integration and social status in free-ranging rhesus macaques (Macaca mulatta) predict anatomical and physiological markers of immunity. We used data on agonistic interactions to determine social status, and social network analysis of grooming interactions to generate measures of individual variation in social integration. As measures of immunity, we included the size of two of the major organs involved in the immune response, the spleen and liver, and counts of three types of blood cells (red blood cells, platelets, and white blood cells). Controlling for body mass and age, we found that neither social status nor social integration predicted the size of anatomical markers of immunity. However, individuals that were more socially connected, i.e., with more grooming partners, had lower numbers of white blood cells than their socially isolated counterparts, indicating lower levels of inflammation with increasing levels of integration. These results build upon and extend our knowledge of the relationship between sociality and the immune system in humans and captive animals to free-ranging primates, demonstrating generalizability of the beneficial role of social integration on health.

社会融合和社会地位可以极大地影响个人的健康和生存。发生这种情况的一种途径是改变免疫功能，这可能对社会环境的变化高度敏感。然而，我们目前对社会性如何影响可以充分实现社会动态的自然人群中的免疫标记的理解有限。为了解决这一差距，我们询问了自由放养的恒河猴 ( Macaca mulatta ) 的社会融合和社会地位是否) 预测免疫的解剖学和生理学标志物。我们使用激动互动的数据来确定社会地位，并使用社交网络分析梳理互动来衡量社会整合中的个体差异。作为免疫测量，我们包括了参与免疫反应的两个主要器官脾脏和肝脏的大小，以及三种血细胞（红细胞、血小板和白细胞）的计数。控制体重和年龄后，我们发现社会地位和社会融合都不能预测免疫解剖标志物的大小。然而，社会联系更紧密的个体，即与更多的美容伙伴相比，他们的白细胞数量低于社交孤立的伙伴，这表明随着整合水平的提高，炎症水平较低。这些结果建立在我们对人类和圈养动物的社会性与免疫系统之间关系的了解之上并将其扩展到自由放养的灵长类动物，证明了社会整合对健康有益作用的普遍性。