{"id":233547,"date":"2026-03-18T02:23:39","date_gmt":"2026-03-18T07:23:39","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2026\/03\/bell-bottoms-today-miniskirts-tomorrow-math-reveals-fashions-20-year-cycle"},"modified":"2026-03-18T02:23:39","modified_gmt":"2026-03-18T07:23:39","slug":"bell-bottoms-today-miniskirts-tomorrow-math-reveals-fashions-20-year-cycle","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2026\/03\/bell-bottoms-today-miniskirts-tomorrow-math-reveals-fashions-20-year-cycle","title":{"rendered":"Bell-bottoms today, miniskirts tomorrow: Math reveals fashion\u2019s 20-year cycle"},"content":{"rendered":"<p><a class=\"aligncenter blog-photo\" href=\"https:\/\/lifeboat.com\/blog.images\/bell-bottoms-today-miniskirts-tomorrow-math-reveals-fashions-20-year-cycle2.jpg\"><\/a><\/p>\n<p>Fashion insiders and beauty magazines have long cited the \u201c20-year-rule\u201d\u2014the idea that clothing trends often resurface every two decades. According to Northwestern University scientists, that observation isn\u2019t just anecdotal. It\u2019s a mathematical reality.<\/p>\n<p>In a new study, the Northwestern team developed a new mathematical model showing that fashion trends tend to cycle roughly every 20 years. By analyzing roughly 37,000 images of women\u2019s clothing spanning from 1869 to today, the team found that styles rise in popularity, fall out of favor and then eventually experience renewal. Along with supporting common perceptions about the life cycles of fads, the researchers say these results could help explain how new ideas spread in society.<\/p>\n<p>The study\u2019s lead author, Emma Zajdela, will present these findings on Tuesday, March 17, at the American Physical Society (APS) <a href=\"https:\/\/summit.aps.org\/\" target=\"_blank\">Global Physics Summit<\/a> in Denver. Her talk, \u201cBack in Fashion: Modeling the Cyclical Dynamics of Trends,\u201d is part of the <a href=\"https:\/\/summit.aps.org\/events\/MAR-J62\/6\" target=\"_blank\">session<\/a> \u201cStatistical Physics of Networks and Complex Society Systems.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Fashion insiders and beauty magazines have long cited the \u201c20-year-rule\u201d\u2014the idea that clothing trends often resurface every two decades. According to Northwestern University scientists, that observation isn\u2019t just anecdotal. It\u2019s a mathematical reality. In a new study, the Northwestern team developed a new mathematical model showing that fashion trends tend to cycle roughly every 20 [\u2026]<\/p>\n","protected":false},"author":427,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2229,219],"tags":[],"class_list":["post-233547","post","type-post","status-publish","format-standard","hentry","category-mathematics","category-physics"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/233547","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/427"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=233547"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/233547\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=233547"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=233547"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=233547"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}