Fashion trends follow recurring cycles of roughly 20 years, with styles rising, fading and returning in a measurable and predictable pattern over time, a mathematical model based on more than a century of clothing data shows. The pattern is driven by a balance between differentiation and conformity in design choices. The findings also indicate that this cyclical structure has weakened in recent decades as fashion becomes more fragmented.
- The analysis tracked approximately 37,000 images of women’s clothing spanning from the late nineteenth century to the present, forming one of the most extensive datasets of its kind.
- Researchers quantified features such as hemlines, necklines and waistlines to convert garments into measurable data across decades for consistent comparison.
- The model captures how designers shift away from overly common styles while remaining within acceptable boundaries of wearability.
- The findings were presented recently at the American Physical Society Global Physics Summit in Denver by lead author Emma Zajdela.
BUILDING THE MODEL: A mathematical model based on one of the largest quantitative fashion datasets has been developed to examine long-term style dynamics across more than a century. The dataset combined historical sewing patterns and runway collections, enabling systematic measurement of garment features over time. Researchers translated design elements into numerical values, allowing fashion trends to be tracked, compared and analysed as a measurable system across decades with consistent parameters.
- The dataset drew on the Commercial Pattern Archive at the University of Rhode Island alongside runway collections spanning from the late nineteenth century to the present.
- Researchers analysed a large set of images of women’s clothing to build a consistent, long-term dataset of fashion features.
- Key garment attributes were measured using custom tools to enable quantitative comparison of design features across decades.
- Emma Zajdela conducted the work as a PhD candidate at Northwestern’s McCormick School of Engineering under Daniel Abrams, professor of engineering sciences and applied mathematics and co-director of the Northwestern Institute on Complex Systems, with co-authors Alicia Caticha of Northwestern’s Weinberg College of Arts and Sciences, and Jeremy White and Emily Kohlberg of Abrams’ research group.
CYCLE IN DATA: Fashion styles rise, fall and return in a repeating pattern that peaks roughly every two decades, forming a measurable cycle across long-term clothing data. The pattern appears as a wave, with gradual shifts punctuated by periodic reversals in dominant styles. One of the clearest examples is hemline length, which has oscillated between shorter and longer forms across successive generations.
- Skirt lengths moved from shorter flapper styles in the 1920s to longer, more conservative designs in the 1950s and then to miniskirts in the late 1960s.
- The cyclical pattern reflects how styles gain popularity, decline as they become widespread, and later re-emerge in modified forms.
- The repeating wave structure was observed consistently across more than a century of clothing data analysed in the study.
- The findings align with the long-cited industry observation that fashion trends tend to return approximately every 20 years.
SHIFT IN PATTERNS: The clear cyclical structure observed across much of the twentieth century has become less distinct in recent decades, as fashion trends increasingly overlap and diverge. Instead of a single dominant style rising and falling in a predictable wave, multiple trends now coexist, reducing the sharpness of cyclical peaks and troughs. This shift reflects a broader fragmentation in fashion, with greater variation and multiple styles coexisting within the same periods.
- Since the late twentieth century, skirt lengths and other design features have shown greater variation within the same time periods.
- The data indicates that no single style consistently dominates, with shorter and longer hemlines appearing simultaneously.
- The weakening of clear cycles suggests that conformity pressures have reduced relative to earlier periods.
- The findings indicate that fashion trends have become more fragmented, with a wider range of styles appearing simultaneously.
