Studying the impact of social status on health

in a laboratory environment affords tighter controls over confounding factors such as status differences in physical environments, food quality and accessibility, ethnicity, and health care allowing for a focused evaluation of the biological impact of social status differentials. In the wild, cynomolgus monkeys (Macaca fascicularis) live in groups comprised of one or more adult males, multiple adult females, and their dependent offspring. Males are usually not related and emigrate between groups one to several times during their lifetime. Adult females are related through one or more matrilines and typically remain in their natal group for life. Female offspring have the same social status as their mother; maternal social status determines number of pregnancies, infant survival, and lifetime Cell Cycle inhibitor reproductive success ( v. S. and van Noordwijk, 1999). Thus, this species selleck screening library experiences suppression of reproductive function

by social status relationships. We have studied the effects of social status on the health of adult female cynomolgus monkeys (M. fascicularis) in the laboratory for nearly 30 years. These monkeys were wild-caught as adults, and in recent years came from a purpose-bred free-ranging colony in Indonesia. The monkeys were housed in small social groups of 3–5 females in rooms approximately 8–10 m3 and enriched with perches, barrels, and manipulanda such as mirrors and toys. The monkeys were fed a diet containing moderate amounts of fat and cholesterol to mimic key dietary constituents consumed in Western societies. When placed in these groups, the monkeys quickly organize themselves into linear social status hierarchies which are usually stable over time ( Shively and Kaplan, 1991). Social status is evaluated by recording the outcomes of agonistic interactions. The animal to which all others in the

group direct submissive behaviors is considered dominant. The monkey that all but the most dominant submits to is considered second-ranking, and so on. Compared to dominant females subordinates receive more aggression almost (Fig. 2A), are groomed less (Fig. 2B), and spend more time alone out of arm’s reach of another monkey (Fig. 2C). Thus, subordinates appear to be subject to more hostility and have less social support than their dominant counterparts. Vigilant scanning (Fig. 2D) of the social environment, a behavior which consists of head swiveling to visually scan the home pen while in a crouched posture, is also a characteristic of subordinate female cynomolgus monkeys in these small groups. These monkeys appear fearful and anxious when engaged in vigilant scanning, as it is often accompanied by lip smacking and grimacing (fear and appeasement behaviors in macaques) (Shively et al., Apr 15 1997) (Shively, Nov 1 1998). We have used telemetered heart rate as an indicator of autonomic function.