The theory of social Darwinism generally claims that individuals, groups and peoples or cultures are subject to the same Darwinian laws of natural selection as are plants and animals. The theory holds that "superior" individuals or groups survived and succeeded while the inferior disappeared, with a consequent benefit to society, and that the existing order must be the natural one. Any individual, group or institution that survives the struggle to exist over a long period of time is regarded as having displayed evidence for its own "natural" superiority and legitimacy, similar to the Darwinian concept of "survival of the fittest". In history, this theory has been questioned because it could be easily used to justify political conservatism, imperialism, and racism.