The horrors of World War I prompted many intellectuals to question long-standing assumptions about civilization, progress, and the alleged superiority of Western cultures over so-called primitive ways of life. In the United States, these questions contributed to struggles between modernity and tradition, reflected not only in politics but also in art and literature. Some of these intellectual movements had their roots in the devastation of Europe; others — such as the Harlem Renaissance — emerged from social upheavals the Great War had wrought at home.