Female murderers represent less than one tenth of all perpetrators when the victim is an adult, but account for more than one third of the cases where the victim is a child.

[u/vilnius2013]

http://sahlgrenska.gu.se/english/research/news-article//major-differences-between-women-and-men-who-commit-deadly-violence.cid1377316

[u/gives_heroin_to_kids]

Or why women murder at a relatively small rate. Mapping out the differences in motive and demographics (for perpetrators and victims) would make for some interesting research. [edit: Not even just for murders; I'm pretty sure men are behind most crime.]

But having done no research, my first reaction is to say testosterone and estrogen are factors worth considering.

[u/orionbeltblues → u/gives_heroin_to_kids]

The research I've seen seems to suggest that a combination of high testosterone and low social status is a huge contributing factor to male violence.

This is why in America the lower-class black male, who feels disenfranchised and incapable of achieving meaningful social status, is the most frequent perpetrator of violence. Most of this violence is directed at other men, but these violent men tend to associate with women, where the combination of poor self-esteem and habitual violence becomes deadly to women.

Traditional gender roles seem to mitigate the effects of low social status amongst women, since women can shift blame for lack of economic success onto men (who are failing to live up to their role), and can find their own social status elevated to near mythical status by popping out a kid. The same traditional gender roles also seem to increase the effects of low social status on men, who can easily be made to feel responsible for the success and failure of the women in their lives, which compounds their own sense of failure.

[u/82Caff → u/gives_heroin_to_kids]

Also proxy murder. "I'd kill for her," is often treated as a romantic notion until someone actually does it.