You need to go one step further here and as: Why are so many young men in the US mentally disturbed. They might not have been born that way but made that way.

For example there is a correlation between circumcision and aggression and PTSD. But the US medical establishment doesn't want to look for a causation. If they found one they would loose a lucrative source of income.

There is also a correlation between raised by a single mother and aggression, including sexual aggressing. No one likes to look for a causation either. That would piss of the feminists.

Then there is lack of male teachers at US schools.