Scientists have, for the first time, developed a mathematical model based on 3D facial scans that enables computers to objectively perceive gender.
Researchers said the computers can mimic human perception of gender.
A multi-disciplinary team of scientists at The University of Western Australia developed the mathematical model that matches the gender scores people give to human faces ranging on a continuum from very masculine to very feminine.
Lead author Syed Zulqarnain Gilani said the model will be useful in quickly and accurately evaluating gender scores in research such as investigating the relationship between masculinity and femininity and health, and in evaluating cosmetic facial surgery in terms of attractiveness, pre- and post-operation.
"Until now the tool-of-choice for getting a gender score has been to call in subjects - sometimes as many as 300 per study - and to recruit raters to give each subject's face a score. Sometimes almost 700 raters might be needed for a study, giving as many as more than 22,000 ratings which then have to be evaluated," Gilani said.
"This is a very cumbersome and slow process," he said.
Gilani and his team recruited 34 female and 30 male students aged about 20 and of different races, and invited 75 raters to give each of the 64 faces a gender score.
Having analysed the raters' scores, the team developed an algorithm that combines the two forms of distances.
"Our results suggest that the human cognitive system employs a combination of Euclidean (ruler) and geodesic distances (contours) between biologically significant landmarks of the face for gender scoring," Gilani said.
"Our mathematical model is able to automatically assign an objective gender score to a 3D face with a correlation of up to 0.895 with the human subjective scores," he said.
The research was published in the journal PLOS One.