Gender, like beauty, lies in the eyes of the beholder, it seems. A study shows that even if you are male, your face may appear to be that of a female to an onlooker.
"It's the kind of thing you would not predict - that you would look at two identical faces and think they look different," says study author Arash Afraz, from Massachussets Institute of Technology's (MIT) McGovern Institute for Brain Research in the US.
He and two colleagues from Harvard, Patrick Cavanagh and Maryam Vaziri Pashkam, conducted research into why this happens.
When people view computer-generated faces, stripped of all other gender-identifying features, there emerges a pattern of biases, based on location of the face, reports the journal Current Biology.
Researchers showed subjects a random series of faces, ranging from the very male to very female, and asked them to classify the faces by gender, according to an MIT statement.
Participants were told to fix their gaze at the centre of the screen, as faces were flashed elsewhere on the screen for 50 milliseconds each.
Assuming that the subjects sat about 22 inches from the monitor, the faces appeared to be about three-quarters of an inch tall.
The patterns of male and female biases were different for different people. That is, some people judged androgynous faces as female every time they appeared in the upper right corner, while others judged faces in the same location as male.
Afraz believes the same thing happens in the brain. In the visual cortex, where images are processed, cells are grouped by which part of the visual scene they analyse.
The smaller the image, the fewer cells are activated, so cells that respond to female faces may dominate, while in another part, cells that respond to male faces may be more dominating.