Social Darwinism, Imperialism was the natural expansion and success of a well-evolved culture, and this expansion would help remove or improve underperforming lifestyles.
Social Darwinism
Only the best survive. The idea that humans, like animals and plants, compete in a struggle for existence in which natural selection results in "survival of the fittest."
Social Darwinism was used to justify imperialism, racism, and laissez-faire (i.e., conservative) social and economic policies.