Why do some faces look male and other female and some neutral?

Answer 1

Prenatal exposure to testosterone and estrogen changes the bone density and shape of the baby regardless of gender. Masculine faces have been exposed to higher leves of testosterone while more feminine faces have been exposed to higher levels of estrogen during fetal growth. A neutral face may mean a lowered exposure of either hormone or may be genetic traits.

Also, people tend to conceive angular faces as more aggressive and ovoid faces, the opposite, when the person may have a completely different personality. This is due to evolution of intersocietal cues that gave human beings an idea of what a person was capable of in simple times.

Answer 2

Hormones have a large impact on the masculinity/femininity of the face.

Due to testosterone, men have broader jaws, larger orbital bones (i.e., jutting brow), more facial hair, rougher skin, and straight eyebrows, among other things.

Women have a more curved skull, more arc in their eyebrows, a less prominent jaw, and softer skin due to the extra layer of fat.

The first is considered masculine because it looks "more powerful" -- bulkier, heavier, assertive/aggressive. The second is feminine because it appears gentler and less threatening.

[Females also look female because their faces tend to be more visually expressive. Men by nature tend to wear a "flatter" facial expression.]

Androgynous people are people of either gender who mix traits. You get women like Bridgette Nielson (who definitely looks powerful in the face, but is still an obvious female), or a guy with more "elfin" looks who still comes across as male.

Girls seem to appreciate the "sensitive" yet masculine look, since the purely masculine might seem too threatening. A lot of rock singers back in the 70's and 80's played up this "elfin" look (Shaun Cassidy, David Cassidy, etc.) and girls were falling for them left and right as "cute."