[cm2187]

A disproportionate amount of movies are about crime stories. Most policemen and criminals are young and men (today, and even more in the past). For the same reason most war movies will also be dominated by young men. Same thing for western movies, the role of women at the XIX wasn't to hold the gun, and guns is what keeps the audience entertained. Why would it be surprising to have a disproportionate amount of young males on screen given the sort of stuff the audience watches?

For the same reason I would expect to see a disproportionate amount of policemen, soldiers and criminals.

They should do that by genre. I would be surprised if comedies, romance, or drama would be much imbalanced.

[AlecSchueler]

There is a by-genre section in the article which shows little deviation in the trend across the board.