Charles Darwin’s theory of evolution by natural selection had a profound impact on both science and society. At the end of the 19th Century, sociologists like Herbert Spencer took Darwin’s theories and applied them to racist and prejudiced understandings of human social life. Spencer coined the phrase “survival of the fittest”. He was a supporter of social Darwinism. Social Darwinism was a belief that the “strong” members of society were also the most wealthy and successful, while the “weak” were not. Eugenicists like Karl Pearson claimed that human traits, like intelligence or “feeblemindedness”, were heritable and could therefore be reduced in the population through controlled breeding.