In some individuals who engage in sexual violence, aggression and sexual arousal states may be reinforcing rather than mutually antagonistic.

“Again, like rough sex, people that want to have fighting, or violence, or aggressiveness in order to be sexually aroused, and fetishes. And in fact, when we made that discovery initially, it raised the question in my mind whether some people that are serial rapists, for example, and engage in sexual violence might, in some level, have their wires crossed in some way, that these states that are supposed to be pretty much separated and mutually antagonistic are not, and are actually more rewarding and reinforcing.”