Theory that persons, groups, and "races" are subject to the same laws of natural selection as Charles Darwin had proposed for plants and animals in nature.
Social Darwinists, such as Herbert Spencer and Walter Bagehot in England and William Graham Sumner in the U.S., held that the life of humans in society was a struggle for existence ruled by "survival of the fittest," in Spencer's words. Wealth was said to be a sign of natural superiority, its absence a sign of unfitness. The theory was used from the late 19th century to support laissez-faire capitalism and political conservatism. Social Darwinism declined as scientific knowledge expanded.