Styles of Male Social Behavior and Their Endocrine Correlates Among High-ranking Wild Baboons

We have previously studied the relationship between dominance rank and physiology among male olive baboons (Papio anubis) living freely in a national park in Africa. In stable hierarchies, such males have distinctive secretory profiles of glucocorticoids and of testosterone. We find that these endocrine features are not, in fact, purely markers of social dominance; instead, they are found only among dominant males with particular stylistic traits of social behavior. One intercorrelated stylistic cluster revolved around the intensity with which the male is involved in sexual consortships (e.g., frequency of copulation, of grooming, degree to which feeding is suppressed by being in consortship). Males most involved in such consortships had the lowest basal cortisol concentrations and smaller cortisol stress-responses. A second stylistic cluster revolved around the degree of social affiliation (e.g., rate of grooming and interacting positively with non-estrus females and infants). Males who were highly affiliated had low basal cortisol concentrations and an attenuated cortisol stress-response. A third cluster revolved around the degree to which males could distinguish between highly threatening interactions with rivals and neutral or mildly threatening ones. Males most adept at this had lower basal cortisol concentrations. These behavioral/endocrine clusters were independent of each other. This suggests that the same adaptive physiological feature (e.g., low basal cortisol concentrations) may arise from different and independent personality styles. © 1992 Wiley-Liss, Inc.