Research into the reasons and causes of domestic abuse is contentious, and most specialists believe that many different cultural, emotional, psychological and physical factors come into play. There are at least four sharply defended schools of thought regarding why men hit their intimate partners.
Because of the patriarchy
A foundation of mainstream feminist thought, the dominant theory of the past 40 years holds that domestic violence is the product of socially sanctioned control. Elizabeth Sheehy, professor of law at the University of Ottawa and author of Defending Battered Women on Trial, believes that men are violent toward women because they reap material rewards. "Control over another person is inherently intoxicating to many," she told me, via e-mail. "But they also gain access to women's labour in the home, to women's sexuality, to their attention, to their child-bearing and rearing, to their money, to their silence (some men hit to shut women up)."
Prof. Sheehy believes that Canada has strict domestic-violence laws, but that they're weakly enforced. Gender equality, not therapy, will be the lasting cure. "When you look at the differences among countries of the world, there is overwhelming evidence that male violence against women decreases with gains in women's equality."
Because they witnessed domestic violence growing up
According to social-learning theory and related schools of thought, some men hit because they were hit as children, or because they witnessed violence between their parents. David Adams, still a stalwart supporter of the battered-women's movement, was co-founder (in 1977) of Boston-based Emerge, which bills itself as the first counselling program for batterers in the United States. He grew up in Vermont, where his mother died partly as a result of his father's abuse. Dr. Adams didn't become an abuser – he credits other positive influences, including a woman who was a second mother to him.
"The power and control model is useful for understanding the frequency of male violence as a social problem. But one weakness of it is that it doesn't give enough information about why one individual man batters and another does not." Without an influence to steer them elsewhere, Dr. Adams believes, "children associate with the more powerful parent. … If you have grown up as a product of violence and fear," resorting to violence becomes a way of creating psychic, emotional and physical space.
Women don't react to witnessing abuse in the same way or with the same consequences because patriarchal expectations don't allow them to, or force them to.
Because of neurochemical imbalances
Researchers such as Kenneth Corvo at Syracuse University's School of Social Work claim domestic abuse is caused by early and lasting neurophysiological impairment. There may even be a genetic component. A 2006 study of domestic-violence perpetrators found abnormalities in the way they metabolized serotonin and testosterone (which men have in much greater abundance). It also found impaired connections between the cortex and the amygdala – which plays a crucial role in memory, decision-making and emotional reactions. All those things contribute to "overreactivity to stimuli, exaggerated fight/flight and anxiety/rage reactions, and an impaired ability to quell arousal or to cope."
Prof. Corvo later concluded in one of his own papers: "Early life stress such as abuse and related adverse experiences cause enduring brain dysfunction." In person, he says, "The data points pretty clearly to male risk factors and psychological factors, rather than the patriarchy … There's a minor influence for cultural coding. But it's so much less than for the psychological."
Because women hit men
This is the most fractious argument in the field of domestic violence. In the 1970s, the University of New Hampshire's Murray Straus, a seminal sociologist in the field of domestic violence, conducted a wide-ranging survey that revealed that women attacked men as frequently as men attacked women. He didn't believe the results, and conducted a second survey, which replicated the findings. Women's violence toward men is "the single biggest risk factor in women getting hit," says Prof. Straus, now 88.
He is, however, oversimplifying the data. Katreena Scott, a psychologist and domestic-violence researcher at the University of Toronto, worked with Dr. Straus in the past. "It's true that when we are discussing low-level violence" – i.e. the vast majority of abuse – "where there is no injury, no fear, no trauma, there is gender symmetry," says Dr. Scott. "I often call this stuff 'relationship violence.' Men and women do swear, yell, slap, push and grab each other in anger and frustration at about equal rates."
But, she says, when the violence becomes more severe, and is measured by impact – "when it promotes fear, when it leads victims to start to change their behaviour to avoid being abused, when it is potentially injurious or lethal, men predominate as perpetrators." In work to be published this spring, Prof. Scott has examined power differentials within couples – not only related to gender, but also to which partner controls access to housing or immigration status. "It looks to me like the fundamental feminist assumption around power differences holds," she says. "The person with the least power is the one likely to be abused, and this is true regardless of whether they are men or women."