Studying sex differences seldom gets boring. The Darwinian process of sexual selection, in which genes that improve an individual’s reproductive success get inherited by the fruits of that reproduction, does a good job explaining sexual dimorphism (male-female differences) in these traits.
For most of our evolutionary past, bigger men fended off rivals for female attention and out-competed other men to secure status and resources that made them useful contributors to a family. These advantages offset the energetic costs and higher disease risk of building a bigger body. But what of other manly features? What use is masculine hairiness? Or those features that tend to distinguish male from female faces.
Read the full, original story: Why the Masculine Face? Genetic Evidence Reveals Drawbacks of Hyper-Masculine Features