Final answer:
Social Darwinism is the social idea that Darwin's theory of natural selection was twisted to justify poverty and racism. It endorsed the notion that social inequalities were the result of 'survival of the fittest,' naturalizing the success of the wealthy while denying assistance to the poor and marginalized.
Step-by-step explanation:
The social idea that used Darwin's theory of natural selection to justify poverty and racism is known as social Darwinism. This concept was largely promoted by British writer and engineer Herbert Spencer, who introduced the phrase "the survival of the fittest." Social Darwinism is based on the misinterpretation of natural selection to argue that social, economic, and racial inequalities were a result of biological superiority and that intervention to assist the less fortunate was counterproductive, as it could lead to the survival of traits deemed inferior.
In its application, social Darwinism provided a pseudo-scientific rationale for societal hierarchies and justified the wealth and power of the elite as natural and deserved.
Critics, however, pointed out that this ignored the lack of opportunities and unequal playing fields that many people faced. Despite its initial popularity among certain circles, the theory fell into disrepute as it became associated with eugenic ideologies and extreme racial discrimination.