Study : It has long been a colour which is guaranteed to turn heads.  But now researchers believe they have found the real reason why men prefer ladies who wear red.

Put simply, they think a scarlet-clad woman is more likely to sleep with them on a first date. Most men thought choosing to wear red meant a woman were more likely to sleep with them.

Psychologists who studied 120 male students aged 18 to 21 discovered that most thought choosing to wear red meant a woman had "greater sexual intent" and was more likely to jump into bed with a man than someone who opted for more neutral colours.

They also found that the item of clothing in question does not need to be a revealing top as volunteers were asked to judge a woman's sexual intent based only on the colour of an ordinary tee-shirt.

The findings, published in the Journal of Social Psychology, confirm the powerful influence the colour of clothing has on how men perceive the opposite sex.

Psychologists at the University of South Brittany in France enlisted 120 male undergraduates and split them into four groups.

Each volunteer spent 30 seconds looking at an image of the same 20-year-old woman but with the colour of her top varied for each group from red, blue, green or white.

The students then completed a questionnaire which asked them to rate, on a scale of one to nine, how attractive they thought the woman was. They also had to rate her in terms of how likely they thought it was that she would have sex with a man on the first date.

The woman was judged to be most attractive when she was wearing the red top, followed by white, blue and finally green.

She was also judged, by a significant margin, to be most likely to agree to sex when she wore red, followed by blue, green and finally white.

In a report on their findings, the researchers said the results supported their hypothesis that men see red as an invitation for sex.

Previous studies have shown that men will ask more intimate questions of a woman and sit closer to her if she is wearing a red rather than green blouse. Research has also suggested female hitch hikers who choose a red top have a better chance of getting more lifts from male drivers but not from female ones.

The University of South Brittany's study found: "Studies have shown that red is connected to lust and romantic love as well as to female fertility.

"But biological evolution could also explain the importance of redness. During their fertility phase, the perineum of female baboons, macaques and chimpanzees becomes red, probably to attract males.

"For the first time, our experiment shows clothes have the ability to lead men to perceive a woman wearing a red tee-shirt as having greater sexual intent than one wearing blue, white, or green."

Psychologist Dr Glenn Wilson, visiting professor of psychology at Gresham College in London, said research also shows men wearing red are more attractive to women because they are seen as having higher status.

"But women in red are attractive to men because of its passionate associations. These effects operate unconsciously and probably derive from the fact that red is a significant colour in nature, signalling danger and causing excitement."