The Age

A warm-up could lead to a big night in the bedroom

By Julie Robotham
The Age (Melbourne)
September 12 2002

Women, like other female mammals, have a distinct "heat" period of heightened sexual desire, scientists say.

But the biological urge to have sex when procreation is most likely may be all but obliterated by the constraints of society and expectations of good behaviour to the extent that some women do not notice cyclically influenced changes to their libido.

"Recent evidence based on women's olfactory and visual perception and men's olfactory perception suggests that women experience recurring periods of increased attractiveness and (desire)," around ovulation, wrote Spanish researchers Dr Juan Tarin and Dr Vanessa Gomez-Piquer in the journal Human Reproduction this week.

Anthropologists had believed humans had lost the heat period during evolution, as increasing brain size resulted in conscious control over sexual behaviour.

But the University of Valencia doctors found this assumption was contradicted by research, in which women's brain scans showed greater response to pictures of nude men when they were ovulating than around menstruation. Other studies, from the UK and Japan, showed women rated classically masculine face shapes as more attractive around ovulation, but not at other times. And in US research, men had found the scent of ovulating women's sweat more attractive than sweat from the same women at other stages of their cycle.

Professor Marita McCabe, a psychologist at Deakin University, said the subject was controversial and unpopular because, "a lot of people do not want to see humans as being subject to biological drives".

Women's awareness of their heat period could be reduced by, "social overlays, monogamy, personality, compatibility, all those loving, caring, nurturing aspects of women... there's no doubt for human females a lot of social and psychological factors affect arousal, such as fatigue, stress, level of engagement with partner, body image, self-esteem and mood."

Whether a woman would acknowledge that she was in heat depended on her attitude to social convention, said Dr McCabe. "I think some people are much more in touch with their biological propensities . . . Some women mid-cycle would be aware they are very aroused and attracted to attractive men. Some would say, 'that smell is really raunchy,' and be very aware of the biology of it."

Professor McCabe's research had shown women in long-term relationships were more likely to want sex with their partners around ovulation if they found them very physically attractive, and were more likely to want sex when they were unlikely to conceive if they saw the man as a steady, good provider but not especially attractive. Heat in humans, "may still be playing an evolutionary role", she said.

Professor Lorraine Dennerstein, the director of the office for gender and health at the University of Melbourne's department of psychiatry, said women with a very high sex drive might not notice the influence of a biological heat. But women with lower libido might notice they were only interested in sex during the time leading up to ovulation.

Copyright 2002 The Age Company Ltd.