People are biased in recognising faces of their own sex, a new study has found.
Dan Wright and his colleague at Sussex University's department of psychology found that women were much better at remembering female rather than male faces. And, likewise, men were better at identifying male rather than female faces.
"People are better at recognising faces of their own gender," Dr Wright told The THES. "This complements other research that has shown that people are better at identifying faces of their own race and age."
The researchers recommended that these results be taken into consideration when assessing a reliability of eyewitness reports.
The researchers report that this own-gender bias is partly due to memory of the person's hair.
In the study, 20 female and 20 male Caucasian volunteers aged between 17 and 36 looked at 24 pictures of faces of people who were unfamiliar to them. Half of these pictures showed men and half showed women, of which six in each gender had their hair obscured. The study participants were then shown a second round of faces, some of which they had been shown before but this time the presence or absence of hair varied. They were asked if they could recall any of the images.
The study shows that hair is helpful for females viewing female faces and males viewing male faces. However, memory of hair does not help cross-gender identifications.
According to the study, this own-gender bias could have originated with our ancestors, who were more concerned with identifying those who they were competing with for mates rather than recognising possible mates.
The findings are published in the journal Acta Psychologica.