In a book written just a few years after the end of the 1920s titled Only Yesterday: An Informal History of the 1920s, Frederick Lewis Allen noted that this decade had involved a "revolution in manners and morals." Indeed, many changes in ways of thinking and behaving, most of them actually rooted in the years leading up to the 1920s, were unleashed by this decade's special circumstances and atmosphere.

These changes were influenced by such factors as the impact of World War I (1914–18) and a falling birth rate, as well by the new work patterns, cultural diversity, and general prosperity that marked this period. They involved different roles for women, who entered the workforce and attended college in greater numbers, were more likely to use birth control, and interacted in society more freely. Families were smaller and were now more focused on emotional attachment...