"Our research suggests that red lips and perceived attractiveness are still ­inextricably linked, with red lipstick the most powerful attractor, and one that ­significantly increases visual fixation," Dr. Geoff Beattie, the study's lead scientist, told the UK's Daily Mail. "The practice dates back as far as the ancient Egyptians, who used red lipstick and rouge to enhance their attractiveness."

According to the study, which involved tracking the eye movements of 50 men as they were presented with images of different women, in the ten seconds after meeting a woman for the first time the average man will spend more than half that time looking at her mouth. If she's wearing lipstick, he'll find it difficult to look away: Men gazed at women's lips for an average of 7 seconds while spending just 0.95 seconds looking at their eyes and 0.85 seconds noticing their hair. And the brighter the lipstick shade the better: Pink hues kept men fixated for 6.7 seconds while fire engine red shades held their interest for 7.3 seconds.