Religious ideology and extremism have had an increasing influence on political agendas in the United States and much of the developed world in the past 60 years, with right-wing ideology becoming more prevalent this decade. This article serves as a review of studies investigating the correlations between political ideology, religiosity, right-wing authoritarianism, ingroups/outgroups, and prejudice in an attempt to describe and understand the well-established links between these dimensions. We discuss several group-level theories including Terror Management Theory, Social Identity Theory, Realistic Group Conflict Theory among others to frame the intercorrelations of these constructs in an effort to better understand the underlying mechanisms that drive individuals to embody religious and political beliefs. We then discuss individual-level cognitive and psychological differences such as intelligence, cognitive flexibility, and specific biological and neurological limitations of brain function that may influence people to adopt certain religious and political beliefs. Through a more comprehensive understanding of the underlying mechanisms of religious and political extremism, we may be better equipped to assuage the fear and denigration that is associated with many of these beliefs.
