Who are you looking at? Why women recognise more faces than men

In order to test the often-cited theory that women are better at recognizing faces than men, psychologists Agneta Herlitz and Johanna Lovén of the Karolinska Institutet, Stockholm, Sweden, have compiled a detailed 'meta-analysis' of over 140 existing facial recognition studies. They conclude:

"Our review of the literature … clearly showed that girls and women remembered more faces than boys and men did, irrespective of [the] age of participants. We also found that, in studies using both male and female faces, girls and women remembered more female faces than boys and men did, but not more male faces. However, girls and women outperformed boys and men in [the] recognition of male faces when only male faces were included in the test material."

The theory that women are better at recognizing, discriminating between, and interpreting facial expressions dates back to the 1970s, and many studies have reported that women outperform men on face-recognition tasks. Women have also been found to outperform men across a number of to-be-remembered materials, such as recall and recognition of words, pictures of objects, and object location. Moreover, there is even evidence that this skill develops in infancy. For example, studies of newly born infants found that girls attended more to a female face than infant boys, whereas boys attended more to a moving object, such as a mobile.

Despite a considerable volume of research on the topic of facial recognition, most studies to date specifically address facial recognition from the perspective of various known biases for race, age, and gender. Herlitz and Lovén therefore set out to test the generalizability of women's advantage over men in face recognition.

Their literature review, published in the journal Visual Cognition, scoured published data (including advance online publications) up to May 2013 and encompassed papers on the presence and magnitude of:

• the sex difference in face recognition;
• the sex differences in face recognition of male and female faces; and
• the own-gender bias for males and female faces.

In total, more than 140 papers were assessed. These comprised not only 'conventional' behavioral studies, but also the physical effects on the brains of test participants by measuring the Blood Oxygen Level-dependent (BOLD) response using functional Magnetic Resonance Imaging (fMRI) scans.

Following a detailed statistical analysis (using the Comprehensive Meta-Analysis technique) of all the research, including the fMRI studies, Herlitz and Lovén found that women's face recognition advantage is mirrored in the neural correlates of face processing and face recognition.

Why are women and girls more skilled at recognizing faces? And why are they particularly skilled at recognizing their own gender? Herlitz and Lovén hypothesize that the tendency for females to recognize other females may be related to gender labeling and gender-typed imitations (for example, toy preferences at a young age), which results in girls orienting themselves towards other females, which in turn leads to more individuation experience with female faces:

"… [T]there is some evidence suggesting that the female advantage in face recognition and the female own-gender bias develop during the early years, but additional research confirming this hypothesis is needed."

However, they note that the age at which the female own-gender bias emerges and possibly diminishes has not yet been thoroughly investigated, although one study reported that, for older women, no own-gender bias was observed for either own- or other-age faces. Further studies into the effects of the age of participants and test faces could provide important information about the development and benefits of face recognition.

They also note that, although a large number of studies were reviewed; many more were excluded because they were not specifically focused on gender differences in facial recognition. In addition, further research is needed in order to fully understand the studies that tested recognition of male faces using the Cambridge Face Memory Test (CFMT).