Women get wet for different men depending on their menstrual cycle

The cycle of sexual attraction

If you're a bloke and the woman of your heart's desire is acting like you don't exist, take heart. It could just be the wrong time of the month.

Women's preferences for certain male faces change with the stage of their menstrual cycle they're at, new research has shown.

Women seem to prefer more masculine male faces when they are mid-cycle and most likely to conceive.

Just before, during and after their period - when they are least likely to fall pregnant - they are more attracted to more feminine male faces, the research by British and Japanese scientists shows.

But if the woman is on the pill, which masks the normal hormonal pattern, she's unlikely to show any preference variation throughout her cycle at all.

The researchers, from the United Kingdom and Japan, believe the preferences shown by the women in the study have an evolutionary basis - with the women seeking the men with the "best" genes when they're most likely to conceive.

This assumes that the women associated masculine features with strong, healthy genes, while the more feminine male faces were seen as kinder and more co-operative, but genetically weaker - a premise supported by some studies done in the past.

But it was the portion of the study that dealt with short-term sexual flings that raises the most controversial notion - that it makes evolutionary sense for women to have affairs with macho men, while choosing less-masculine men with whom to settle down.

When asked to pick the most attractive face for a short-term sexual relationship, the women tended to favour the most masculine faces, while their preferences were more stable when choosing Mr Long Term.

This raises the prickly idea that a woman might be unfaithful so she can snare the best genes for her child, while keeping her long-term partner, the better carer, to raise them.

One of the researchers, Professor David Perrett, from the University of St Andrews in Fife, conceded this was a possibility.

But in an interview with the BBC, he said we could not be sure how women's preferences for faces as measured in the lab would affect their behaviour in real life.