Fashion really repeats itself every 20 years, according to a mathematical model

The hem length varies in cycles. Picture: Emma Zajdela / Daniel Abrams / Commercial Pattern Archive

Mini or maxi? Wide-legged vs. whistles? Narrow or wide tie?

Western consumers know that nothing is permanent in fashion. In the era of fast fashion, consumers are offered new designs and cretons every month.

Most of us don’t take every hook. However, from time to time old clothes are back in fashion.

The old rule of thumb is that you return to the same style every 20 years or so.

A rule has not previously been rigorously studied scientifically. Now mathematicians from Northwestern University in Chicago and a number of other researchers took up the challenge.

Researchers connected Rhode Island the university’s commercial plan archive information for drawings and pictures of fashion collections. They were compared since 1869.

They classified women’s clothing over a period of 160 years and collected data on approximately 37,000 items of clothing.

The researchers measured, for example, the length of the hem, the position of the waist and the design of the neckline.

They then developed a mathematical model. It was used to calculate the rise and fall of trends.

Calculations confirmed that the trends have indeed risen and fallen in a cycle of about 20 years. The length of the hem is a good example of this.

According to researchers, the fashion industry recycles themes and models every two decades.

The new style always settles in between originality and tradition, says Northwestern-on the university’s website one author of the study, mathematician Emma Zajdela.

Zajdela mathematically studies the intricate, complex phenomena of nature and society. Such are the vagaries of fashion.

He presented research related to fashion in March at the meeting of the American Physical Society in Denver.

When the clothing style is too popular, the designers are renewing the lines. The collections change just enough to make them stand out from the crowd.

“It’s a constant effort to be a little different from everyone else. It makes the styles swing back and forth.”

“The system naturally oscillates. We see periods in the data,” says the applied mathematician Daniel Abrams.

Incessantly The 20-year rule no longer applies. Already in the 1980s, short and long skirts were fashionable at the same time.

“Variation increases, uniformity decreases,” says Abrams.

It might still be worth putting an out-of-fashion piece of clothing in the tote bag. Someone may want it in the 2040s. And pay for it.