What’s unhealthy isn’t masculinity or femininity but the demeaning of masculine men and feminine women. The first of the new APA guidelines urges psychologists “to recognize that masculinities are constructed based on social, cultural, and contextual norms,” as if biology had nothing to do with it. Another guideline explicitly scoffs at “binary notions of gender identity as tied to biology.”

From a mental-health perspective, it can be beneficial for women to embrace masculine traits and for men to express feminine ones. Every person will have some mix of the two. But that doesn’t change the reality that women tend to be feminine and men tend to be masculine. Why can’t the APA acknowledge biology while seeing femininity and masculinity on a spectrum?

To be sure, the cult of manhood can be harmful when taken to extremes. Teaching boys—or girls, for that matter—that they should always be stoic, keep their feelings inside and never allow themselves to be vulnerable is a recipe for mental illness. But so is telling boys that aggression, competitiveness and protectiveness is a sign of sickness. The same is true of telling girls that their desire to nurture children is shameful.