How did social Darwinism help eugenics gain support in the late 1800s?

Social Darwinism provided a powerful philosophical and pseudo-scientific framework that helped eugenics gain widespread support in the late 19th and early 20th centuries. By asserting that the principles of natural selection and "survival of the fittest" applied to human societies and social classes, social Darwinists argued that human progress depended on the success of the "strong" and the elimination of the "unfit."123

This perspective encouraged the belief that societal problems were rooted in biological inheritance rather than environmental factors. Consequently, eugenics—coined by Francis Galton—was presented as a logical, scientific method to "improve" humanity by controlling reproduction. The movement gained traction by promising to preserve "good stock" through positive eugenics and to prevent the proliferation of "defective stock" through negative eugenics. By framing these interventions as necessary for the evolution of society, proponents successfully integrated eugenic goals into the cultural and political discourse of the era, influencing legislation and social policy globally.425