The St. Andrews team used 3D scans of men's and women's faces to investigate perceptions of masculinity.
Image credit: University of St. Andrews
"Masculinity has powerful effects on attractiveness and a range of other attributions, such as leadership and trust," says lead author Iris Holzleitner, a PhD student in the University of St Andrews' Perception Laboratory.
"It is important that we understand the physical basis of perceptions and the origins of masculine stereotypes," she continues. "Here, we showed that perceived facial masculinity has several distinct physical origins."
Previous studies have investigated whether masculinity can be measured as the average difference between the face shape of men and women. However, women's perception of masculinity was not found to be consistent with this measure.
In their study - published in the journal Perception - the St. Andrews team used 3D scans of men's and women's faces to investigate these perceptions of masculinity.
Masculinity perceptions cued by body shape?
Holzleitner says that their study broke ground with previous investigations into masculinity and facial shape by testing whether participants' perceptions of masculinity were influenced by cues as to the height and weight of individuals, based on seeing just their faces.
"We also asked people to judge the height and weight of the men in our sample - again just from their faces," says Prof. David Perrett, of the School of Psychology and Neuroscience, who supervised the study.
"We were surprised to find that the facial cues of height and weight we identified predicted perceptions of height and weight much stronger than actual height and weight," he adds.
Prof. Perrett says the findings suggest that people base their perceptual judgements on actual physical differences related to height and weight, but then read too much into these cues. He explains:
"That is, we seem to have learned that, for example, being tall is associated with a more elongated face shape. If presented with the faces of two equally tall men, and one of them has a slightly longer face than the other, we will be likely to think that the man with the longer face is also taller."
This "perceptual overgeneralization" could explain why observers might interpret a taller or heavier man as being more masculine, say the researchers.
"Intuitively, people understand that women and men differ in their average height and weight," Holzleitner concludes. "Our study suggests that facial cues to these traits are overgeneralized when judging masculinity."
A 2011 study on the gendered attributes of faces involved participants looking at pictures of faces that had been computer-manipulated to appear gender-neutral. For each face, the volunteer had to categorize it as male or female by squeezing a ball. Some participants had a soft ball and some had a hard ball.
The researchers behind that study found that participants squeezing the soft ball were more likely to categorize the faces as female, while those handling the hard ball were more likely to categorize them as male. The researchers concluded from this that our sense of touch cues our perceptions of masculinity and femininity.