"Nearly half of all women and men in the United States have experienced psychological aggression by an intimate partner in their lifetime (48.4% and 48.8%, respectively)."
Abusers are about equally men and women. A surprisingly large percentage of those partners are mutually abusive (I forgot if it's more like 25% or more like 50% but both are high IMO). Men hurt women more because men are, duh, stronger.
Why?
The data suggests it’s close to 50-50.