In the literature on children’s interpersonal and intergroup relations, it is inappropriate to say a child is ‘racist’ even in the evidence of the White child refusing to sit near a Black peer in class, or vice versa, or allying with friends to bully that same peer at school. In such cases, this child’s behavior has been referred to as out-group prejudice. Racial prejudice is bound to develop into any of the multiple types of extremism. This article explores the similarities between the adult extremist mindset and children’s prejudice. We present the conceptual constituents of both the extremist mindset and prejudice, and then discuss the convergences between the two; we later present the convergences in the determinants of both extremism and prejudice. The exploration of such convergences allows us to posit that prejudice in childhood may be a marker for extremism in adulthood. The recommendation is therefore to incite researchers to look more into the prejudiced mindset in childhood as a potential marker of the adult extremist mindset, and intervention policy makers to look into factors that buffer the further development of children’s prejudiced mindset into extremist polarized views about the world.