Abstract Genetics and eugenics co-evolved at the beginning of the twentieth century and remained associated through the 1940s and beyond. Early geneticists were far from unanimous in their views on eugenics; some avidly supported the movement, whereas others openly opposed it or chose to remain detached. Academic institutions and scientific societies are currently reckoning with their past associations with eugenics. This article highlights historical connections between the UK Genetics Society and the eugenics movement in Britain. The complexity of these connections is illustrated through case studies of three notable Genetics Society past Presidents—J. B. S. Haldane, R. A. Fisher, and L. S. Penrose—who represent diverse ways that British geneticists engaged with the eugenics movement, from career-long support to science-based opposition. Their contributions to, and critiques of, eugenics are situated in their scientific and historical contexts. We reflect on the historical role of professional genetics organisations in facilitating the rise of eugenics in the early twentieth century, and the present responsibility of the same organisations to combat its contemporary revival.
Aylward et al. (2026) studied this question.