The in-group bias is a well-known social psychology concept that explains the human tendency of supporting those like themselves (the ‘us’) while denigrating those who are different (the ‘them’). In Behave: The Biology of Humans at Our Best and Worst, Sapolsky goes in depth on the dichotomizing process of “us/them-ing”, claiming our mental categorizations to be innate and automatic. Sapolsky dedicates a chapter of Behave to explaining the biological and social reasons all humans, along with a few other species, have this tendency and, more importantly, demonstrates how this simple concept is much more nuanced than at first glance. The purpose of this paper is to look beyond the basic definitions and characteristics of “us/them-ing”, as Sapolsky
