What social theory applies the concept of 'survival of the fittest' to human societies and was often used to justify imperialism?

The concept of "survival of the fittest" as it applies to human societies is best encapsulated by Social Darwinism. This theory emerged in the late 19th century and posited that the same principles governing the natural selection observed in biological evolution also applied to human societies and economies. Proponents of Social Darwinism argued that just as species evolve and survive based on their fitness in nature, human societies progress through a similar struggle for existence.

This ideology was often employed to rationalize and justify the expansion of European imperialism, as it suggested that stronger nations had a natural right to dominate weaker ones. By framing imperialism as a natural and beneficial process, advocates of Social Darwinism believed they were contributing to the advancement of civilization. The theory also influenced social policies and attitudes regarding class, race, and economic competition, reinforcing a belief in inherent human hierarchies.

Utilitarianism, social contract theories, and Marxism focus on different aspects of society and do not incorporate the idea of 'survival of the fittest' in the same way. Utilitarianism is centered on the principle of the greatest happiness for the greatest number, social contract theories deal with the legitimacy of government authority based on consent, and Marxism analyzes class struggle and