RESUMEN
In the 1930s and 1940s, the Nazis used science as a tool for shaping state policy. One of the most abhorrent aspects of scientific collaboration with the Nazis at that time was the broadly defined field of "race psychology." In this article, we focus on German comparative research on the psychology of Poles and Germans, as analyzed by Tadeusz Tomaszewski, who is considered to be one of the founders of contemporary Polish psychology. We illuminate this episode from the history of science by providing a full translation of Tomaszewski's article published in 1945 on a research project led by Rudolf Hippius conducted in 1942 in Poznan (in occupied Poland) in the name of the political interests and ideology of the Nazi regime. We also shed light on the historical context of Tomaszewski's article, which facilitates the understanding of the core ideas of race/ethnic psychology per se; the sociohistorical context also provides the framework in which the other research articles that we refer to must be read. Reading Tomaszewski's text today will enhance our understanding of the relationship between science and politics, and serve as a warning for researchers today. (PsycInfo Database Record (c) 2022 APA, all rights reserved).