Are those between clear gender identity more promiscuous?
Psychologists have found that adult females who have prominent chins are more sexually active than those with softer features, yet are less attractive to men looking for a long-term partner.
Larger chins on women are often caused by a high level of the male growth hormone testosterone, present in all women in various amounts.
The hormone also increases sexual assertiveness in a woman, a tendency more commonly attributed to males.
It was concluded that men will shun women with such masculine features when looking for a long-term partner because they fear being cuckolded.
People hate cheating spouses because they've violated the most sacred human contract there is: to work together to create a family where each member is defended against the world. As we can trust our fellow citizens less and less, this becomes more important.
Masculinized women, in addition to being a blight on the workplace, are more likely to cheat. They lack the complementary force to a male that makes a marriage work. So now you've got a problem. Men who are in touch with their instincts avoid them so they can have functional families instead of joining the world at large in its dysfunction.