Criticism of the Duluth Model has centered on the program's insistence that men are perpetrators who are violent because they have been socialized in a patriarchy that condones male violence, and that women are victims who are violent only in self-defense. Some critics argue that "programs based on the Duluth Model may ignore research linking domestic violence to substance abuse and psychological problems, such as attachment disorders, traced to childhood abuse or neglect, or the absence of a history of adequate socialization and training." Others criticize the Duluth Model as being overly confrontational rather than therapeutic, focusing solely on changing the abuser's actions and attitudes rather than dealing with underlying emotional and psychological issues. Donald Dutton, a psychology professor at the University of British Columbia who has studied abusive personalities, states: "The Duluth Model was developed by people who didn't understand anything about therapy," and also points out that "lesbian battering is more frequent than heterosexual battering." Philip W. Cook points out that in the case of homosexual domestic violence, the patriarchy is absent: there is no male dominance of women in same-sex relationships, and in fact, female on female abuse is reported more than twice as frequently as male on male abuse. Furthermore, some critics point out that the model ignores the reality that women can be the perpetrators of domestic violence in heterosexual relationships, as well.