Back in Fashion: Modeling the Cyclical Dynamics of Trends

Many people have experienced firsthand the idea that “fashion comes back,” from bell-bottom jeans to miniskirts. Using a new dataset of more than 35,000 images of women’s dresses from 1920-2022, we measured how necklines, waistlines, and hemlines changed over time. We find that fashion trends cycle roughly every 20 years, consistent with industry knowledge, while also becoming more diverse since the mid-1980s. To explain these patterns, we developed a mathematical model based on the idea from psychology of “optimal distinctiveness”: for innovations to succeed, they must be different from others, but not too different. Beyond fashion, this research offers insight into how the interplay of creativity and conformity shapes collective behavior across a variety of social systems.