In the search for the root of intimate partner violence (IPV), intranasal oxytocin was administered to a control group and a group of participants with aggressive tendencies. Participants were then surveyed on how willing they were to engage in 5 behaviors towards their romantic partner. What they found was that oxytocin increased IPV inclinations only among the participants with a predisposition towards aggressive tendencies. Oxytocin decreases trust and prosocial behavior in individuals with interpersonal difficulties. This, coupled with its role in relationship maintenance, illustrates that oxytocin serves to instill a sense of territoriality and protectiveness towards a mate.