Blushing in shades of crimson, scarlet or deep rose, a girl is regarded as prettier and more desirable, research shows.
She is also more likely to be asked out on a date - and have more money lavished on her during the outing.
The researchers said it appeared they were driven by primal instincts that associate the colour with sex.
The study, carried out at the University of Rochester in the U.S., involved a series of experiments in which men were shown a photo of a 'moderately attractive' young woman.
In some cases, the colour of the border framing the picture was changed, in other cases the colour of the woman's blouse varied. Red, blue, green, grey and white were tested. In all cases, red was judged the most attractive.
The men were much more likely to ask out a woman wearing red. And they estimated they would spend almost twice as much on her as one in blue.
Despite the clear effect, the men insisted colour played little role in their choices, suggesting they were oblivious to the power of red.
The study, published in the Journal of Personality and Social Psychology, claims to provide the first hard evidence of 'society's enduring love affair with red'.
From the red body paints used in ancient fertility rituals, to the phrase 'red light district' and the red hearts of Valentine's Day, the colour has long been associated with romance.
In the animal world, red often signals a female is at her most fertile, with female baboons and chimps blushing conspicuously at this time.
Men are not alone in being attracted to red. The research suggests a man in scarlet is just as irresistible to women. [via dailymail]