Although somewhat unusual, evolutionary psychology can also explain conflicts in politics and the international society. A journal article by Anthony C. Lopez, Rose McDermott and Michael Bang Petersen uses this idea to give out hypothesis to explain political events. According to the authors, instincts and psychological characteristics developed through evolution is still existent with modern people. They suggest human being as "adaptation executers"; people designed through natural selection, and not "utility maximizers"; people who strive for utility in every moment. Though a group of people, perhaps those who are in the same political coalition, may seem as if they pursue a common utility maximization, it is difficult to generalize the theory of "utility maximizers" into a nation-view because people evolved in small groups. This approach helps scholars to explain seemingly irrational behaviors like aggressiveness in politics and international society because "irrational behavior" would be the result of a mismatch between the modern world and evolutionary psychology. For example, according to evolutionary psychology, coalitional aggression is more commonly found with males. This is because of their psychological mechanism designed since ancestral times. During those times men had more to earn when winning wars compared to women (they had more chance of finding a mate, or even many mates). Also, the victorious men had more chance of reproduction which eventually led to the succession of aggressive, eager-to-war DNAs. As a result, the authors hypothesize that countries with more men will tend to show more aggressive politics thereby having more possibility of triggering conflicts within and especially among states. Indeed, some exceptions do exists in this theory as this is just a hypothesis. However it is viable enough to be a hypothesis to be tested to explain certain political events like war and crisis. On an individual level terrorism has been explained as a display of psychopathological personality disorders. Terrorists have demonstrated to show narcissistic personality traits (Lasch, 1979, Pearlstein, 1991). Jerrold Post (2004) argues that narcissistic and borderline personality disorders are found in terrorists and that mechanisms such as splitting and externalization are used by terrorists. Others such as Silke (2004) and Mastors and Deffenbaugh (2007) refute this view. Crenshaw (2004) showed that certain terrorist groups are actually careful in not enlisting those demonstrating pathology. The authoritarian personality theory has also been used as an explanation for terrorist behavior in individuals. In terms of explaining reasons for which individuals join terrorist groups, motivational theories such as need for power and need for affiliation intimacy are suggested. Festinger (1954) explained that people often join groups in order to compare their own beliefs and attitudes.