Explain social darwinism and how it applies to imperialism

Social Darwinism held that those made better or worse by industrialization were based on the natural predisposition of the people effected. For those who were made better off, the success of those people demonstrated that they had a well-evolved culture and this expansion would help remove or improve underperforming cultures, which were those "chosen" by the fact that they were performing poorly.

All in all, according to the Social Darwinist, Imperialism was the natural expansion and success of a well-evolved culture and this expansion would help remove or improve underperforming cultures.
social darwinism was used to justify imperialism because social darwinism was the idea that the stronger race would survive and the weaker would die off. in many cases imperialism was justified by the thought that the country being taken over was weaker and needed help, thus the "greater country" could force its customs on the other country.