One study argued that it was the above-cited Dekeseredy et al. that in fact improperly contextualized partner violence; Dekeseredy's campus study was based around asking women and only women if their violence was in self-defense, and not permitting the same for men. This results in counting men who had defended themselves as perpetrators, and counting women who may have engaged in ex post facto justification of their violence, a noted trait of psychological abuse, as victims. The study further found that studies from the US Department of Justice did not contextualize violence simply by not counting women perpetrators until forced to by the US Centers for Disease Control (CDC). Other studies that decontextualized partner violence included labeling aggregate findings of motivations for violence that included the desire to coerce or control the partner or being angry with the partner as "striking back" when such questions revealed that women scored equal to or higher than men in desires to use violence out of simple anger or to coerce and control the partner. This, however, is contradicted by other reviews which found women's primary motivation were triggered by anger or self-defense while men's motivation was more about control. Some studies have also postulated that when other factors such as allowing both or neither gender to claim self-defense, or simply including male victims and female perpetrators in the sample, the results were at or near parity for perpetrators and victims, with the results near parity sometimes favoring females and sometimes favoring males. Another large study reveals that women are between two and three times as likely to be the offender in non-reciprocal partner violence. The study suggests that while women are far more prone to be the sole offender, reciprocal violence where both partners use violence has higher frequency of serious injuries, and that these injuries more often have female victims than male.