“Research focusing on specific violent events shows that women almost always employ violence in defense of self and children in response to cues of imminent assault in the past and in retaliation for previous physical abuse. […] Studies of actual cases lend no support to the facile claim that homicidal husbands and wives “initiate similar acts of violence.” Men often kill wives after lengthy periods of prolonged physical violence accompanied by other forms of abuse and coercion; the roles in such cases are seldom if ever reversed. Men perpetrate familicidal massacres, killing spouse and children together; women do not. Men commonly hunt down and kill wives who have left them; women hardly ever behave similarly. Men kill wives as part of planned murder-suicides; analogous acts by women are almost unheard of. Men kill in response to revelations of wifely infidelity; women almost never respond similarly, though their mates are more often adulterous. The evidence is overwhelming that a large proportion of the spouse-killings perpetrated by wives, but almost none of those perpetrated by husbands, are acts of self-defense. Unlike men, women kill male partners after years of suffering physical violence, after they have exhausted all available sources of assistance, when they feel trapped, and because they fear for their own lives.”
Pages 80-81 in Russell P. Dobash, R. Emerson Dobash, Margo Wilson and Martin Daly, 1992, “The Myth of Sexual Symmetry in Marital Violence,” Social Problems 39(1): 71–91.