Historians of science have often presented the inter-war period as a time when British scientific communities radically questioned existing scholarship on ‘race’. The ascendancy of genetics, and the perceived need to challenge Nazi ‘racial’ theory have been highlighted as pivotal issues in shaping this British revision of ‘racial’ ideas. This article offers a detailed analysis of British scientific thinking in the inter-war period. It questions whether historians have exaggerated or oversimplified the prevalence of anti-‘racial’ reform. It uses a wide range of scientific writings to consider issues of continuity and change in ‘racial’ thinking in mainstream British scientific communities. The article probes the relationship between science and politics, focusing on the extent to which ideological factors affected both the scientific agenda and conclusions as regards ‘racial’ issues. Far from dismissing the idea that events in the inter-war period triggered changes in the way in which British scientists dealt with ‘race’, the article argues that the seeds of the post-Second World War international scientific rejection of ‘race’ were sown in inter-war Britain amid considerable ambivalence and discord.

We must remember that the investigator, whether a biologist, an economist, or a sociologist, is himself a part of history, and that if he ever forgets he is a part of history he will deceive his audience and deceive himself.J. B. S. Haldane, Heredity and Politics, 1938