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Why are lips red? © Getty Images

Why are lips red?

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Whether a sexual signal or thin-skinned sensitivity, the answer might make you blush.

Asked by: Matthew Merton, Bournemouth


In the 1960s, zoologist Desmond Morris suggested that a woman’s lips evolved to signal sexual receptiveness, by mimicking increased blood flow to the genitalia. Research has shown that men do find the colour red attractive, but a 2012 study at the University of Kent found that men didn’t prefer a red vulva, specifically, over a pink one. So lip colour might just be a consequence of the thinner skin there, which improves sensitivity.


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luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.


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