The social organisation of a group of primates and in particular its aggressive interactions have profound but predictable effects on sexual behaviour. Dominant individuals have prerogative over sexual interactions, but since moving into a social group itself entails changes in endocrine state, one cannot ignore the fact that these endocrine changes may in some way reinforce the nature of the social hierarchy. In paticular, this paper considers how a monkeys endocrine profile may vary according to its social status and how endocrine profiles change in different rank. Most important is the finding that behavioural experiences in the social group may have repercussions for an animals ability to cope with changing circumstances, depending upon whether that individual was of high or low social status. Recent studies using the opiate receptor blocker, naltrexone, suggest that the endogenous opiates may provide a common neural link between the behavioural consequences of social subordination and some of the endocrine changes which accompany this.