Who is known for articulating that "social mobility is harder than we think" in a critical analysis of American society?

William Sumner is recognized for his critical analysis of social mobility and the challenges inherent in it within American society. He was a prominent social scientist and a proponent of social Darwinism, which emphasized the competitive aspects of society and the idea that not everyone has equal access to upward mobility. Sumner's perspective highlighted structural barriers and social inequalities that affect individuals’ ability to improve their socioeconomic status, suggesting that these barriers make social mobility much more challenging than commonly perceived.

In contrast, Horatio Alger is well-known for his stories that romanticize the idea of hard work leading to success, often portraying a more optimistic view of social mobility. FDR, as a political leader, focused on economic recovery and social security during the Great Depression, rather than a critical analysis of social mobility itself. W.E.B. Du Bois, while he did address issues related to race and social inequality, framed his discussions in the context of racial discrimination and its impacts on opportunity, which is somewhat different from the broader societal critique that Sumner provided regarding social mobility.