What is it with men and red lips? A small barrage of questions to my beloved male friends (it's wonderful that they always give me a glimpse into the male brain) confirmed it once again: “It's sexy, cheerful, and lips in cartoons are always red” or “red lips can make the dullest chick look sensual and desirable.” Yes dear ladies, men really think that. French sociologists even found that waitresses with red lipstick would receive more tips than ladies wearing a different color.

But how does this come about? Okay, red is a sexy color, but the attractiveness of this does have a biological basis. According to Adam Pazda, a psychologist from the University of Rochester, reddening features in the face are a result of the female gender ovulating. This is related to a peak in estrogen levels. In other words: red lips remind men of fertile women and that is (consciously or not) very desirable for men. Ahaaa. Do you get it now?

So girls: chest out and lips puckered. At least if you're going for the fertility look.