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Political scientists Alford, Funk, and Hibbing published a 2005 twin study in this journal, where they concluded that genetic factors play an important role in shaping political attitudes and ideologies. Subsequent researchers claimed to have identified genes associated with political behavior at the molecular level. Here, I join previous critics in arguing that Alford and colleagues ’ research method, known as the twin method, rests on the clearly false theoretical assumption that reared-together monozygotic and dizygotic twins experience equal environments. I conclude that the results of Alford and colleagues ’ twin study can be explained completely by non-genetic factors. In addition, I argue that recent gene discovery claims are likely false positive findings in much the same way as this has occurred in psychology and psychiatry. I elaborate on the flaws in twin studies, and analyze the evidence put forward in support of the equal environment assumption (EEA) of the twin method