Men with large jaws, flaring cheeks and large eyebrows are sexy, at least in the eyes of our ancestors, researchers at the Natural History Museum have discovered. Facial attractiveness played a major role in shaping human evolution, as studies on our fossil ancestors have shown our choice of sexual partner has shaped the human face. The findings appear in the online, open-access journal PLoS ONE.

The face holds the secret to determining the sex of our ancestors and what makes us attractive to the opposite sex for reproduction.

According to palaeontologists at the Natural History Museum, men have evolved short faces between the brow and upper lip, which exaggerates the size of their jaw, the flare of their cheeks and their eyebrows. The shorter and broader male face has also evolved alongside and the canine teeth have shrunk, so men look less threatening to competitors, yet attractive to mates.

At puberty, the region between the mouth and eyebrows, known as upper facial height, develops differently in men and women. Unlike other facial features, however, this difference cannot be explained simply in terms of men being bigger than women. In spite of their larger size men have an upper face similar in height to a female face, but much broader. These differences can be found throughout human history. As a result, a simple ratio of measures could be used to calculate facial attractiveness in a biological and mathematical way.

Dr Eleanor Weston, palaeontologist at the Natural History Museum said, The evolution of facial appearance is central to understanding what makes men and women attractive to each other. We have found the distance between the lip and brow was probably immensely important to what made us attractive in the past, as it does now.