While it'd be great if people could recognize the beauty in everyone, it doesn't always work that way. People have their own idea of what they find attractive.
Researchers at the Universidad Autonoma de Madrid, in Spain surveyed 266 female students on their own perceived attractiveness, then asked 44 heterosexual men to rate the attractiveness of each woman based on black-and-white, unsmiling pictures.
Independently, the researchers used criteria, such as symmetry, to categorize the women on a scale from average to unique, and youthful to more mature in appearance.
Both men and women agreed that symmetry was more desirable than faces with asymmetrical features. Overwhelmingly, the men were most attracted to women who were categorized as average. And (shocker) the men also reported youthful faces as the most pleasing.
Average faces are more attractive to men? Say what?
There's a scientific explanation for this, though. Men associate average features with high heterozygosity, which means a high genetic variability. More unique looks lead men to subconsciously link the woman with low heterozygosity, also known as inbreeding. Youthfulness is a sign of fertility and health.
So men aren't being shallow after all; they're just following their biological imperative to find a good mate and child-bearer.