Sexual desire depends on status and self-esteem

There is no known link between a woman's hormone levels and her desire for sex; and although men with malfunctioning testicles, experience a rise in libido when they are given testorerone treatment, for men within the normal range, there is no consistent link between hormone levels and sexual activity.

Perhaps, as with monkeys and apes, social status is far more important than hormones in determining who has sex. Barry Keverne and colleagues at the University of Cambridge have shown that castration did not eliminate the dominant male monkeys' sexual interest in females, and no amount of testosterone made the subordinates sexually active.

In contrast, low rank does not suppress the sexual desires of subordinate females. Keverne thinks this is largely because hierarchies amongs the femelas are established through grooming activities rather than aggression.

Keverne believes that the brains of chronically subordinate male monkeys massively over-produce endorphins in response to the constant stress they receive. and can no longer register the endorphin 'reward' of sexual activity, even when it becomes possible.

Keverne concludes: 'The consequences of social exclusion in monkeys are remakably similar to the consequences of mother-infant separation, a cascade of malfunctions at the motivational level paralleled by endocrine and autonomic changes influencing health and well-being.'

Gail Vines in her article extrapolates from the research on monkeys to humans: 'For an active sex life, choose supportive friends, workmates and lovers.'

Barry Keverne, Sub-Department of Animal Behaviour, University of Cambridge, Madingley, Cambridge CB3 8AA (tel 0954 210301). His research is reported in 'Primate Social Relationships: Their Dertminants and Consequences' published in Advances in the Study of Behaviour, Vol. 21, (Academic Press, 1992).