> there are millions of young males in the US alone who are more careful than millions of young females

Yes, and millions of young men in the US who are shorter than millions of young women. What’s your point? Young men are still disproportionately more likely to be in road traffic accidents.

Re testosterone, the keywords you should be searching for are “risk taking behaviour”.

I’m curious also what percentage of time you think the average military driver is being shot at is.