Toronto, May 28 (IANS) Our brain is wired to identify sex based on facial cues and colouring, according to a new study.
Frederic Gosselin, psychology professor and his Montreal University team found the luminescence of the eyebrow and mouth region is vital in rapid gender detection.

“As teenagers, dimorphism (systematic difference between sexes) increases in the nose, chin, mouth, jaw, eyes and general shape of faces,” said Nicolas Dupuis-Roy, study co-author. “Yet we aren’t conscious of how our brain recognises those differences.”

To discover those reference points, Dupuis-Roy and colleagues showed photos of 300 Caucasian faces to some 30 participants. They were asked to identify gender based on images where parts of faces were concealed using a technology called Bubbles.

The investigation found that eyes and mouths, specifically their subtle shading or luminance, are paramount in identifying gender.

Unlike previous studies, which found the gap between the eyelid and eyebrow as essential in gender ID, this investigation found the shades of reds and greens around mouths and eyes led to faster gender discrimination.

“Studies have shown that an androgynous face is considered male if the skin complexion is redder, and considered female if the complexion is greener,” said Dupuis-Roy.

“However, it is the opposite for the mouth. A woman’s mouth is usually redder. Our brain interprets this characteristic as female,” he added, according to a Montreal release.

“A man’s face usually reflects less light around the eyebrows. This is because they are usually thicker. The same applies to the upper lip and chin, which are hairier areas,” Dupius-Roy added, noting people clearly use colour to rapidly identify gender.

The study was published in the Journal of Vision.