This editorial addresses the following questions: Is there a class psychology? In other words, can it be proven that distinctive psychological phenomena are correlated with racial and national differentiations, and with the occupational and religious distributions of human beings? What do we most want to know about the psychological differences discoverable in the various sorts of human beings? How shall we get the knowledge? (PsycINFO Database Record (c) 2006 APA, all rights reserved)