This essay is a defense of the social construction of racialism. I follow a standard definition of “racialism” which is the belief that “there are heritable characteristics, possessed by members of our species, that allow us to divide them into a small set of races, in such a way that all the members of these races share certain traits and tendencies with each other that they do not share with other members of any other race”. In particular I want to defend the “radical” social-constructive thesis that holds “the concept of race is exclusively the product of historical and cultural causes. It claims that humans do not tend to classify people into races when groups with different phenotypes meet, save for particular historical circumstances”. The quoted position is the consensus view among historians, sociologists, anthropologists, and other social scientists who study racialism but has recently been criticized by philosophical defenders of cognitive/evolutionary psychological approaches to racialism. Drawing on developmental studies as well as historical and contemporary cross-cultural research, CEP philosophers point to similarities of racialism across time and space. They hold that social constructionist approaches to racialism cannot explain these similarities. I hold that SC approaches do explain these similarities and that such similarities actually pose a significant challenge to the proposed CEP research program on racialism.