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Why are zippers on different sides of male and female jackets? – Agrima, age 13, Delhi, India

Imagine you’re at a clothing store that stocks items for the whole family. You pick up a white buttoned shirt to try on. The style is pretty plain. Was it designed to be worn by a woman or man?

There may be a clue: Many women’s shirts have buttons on the left side, while men’s shirts usually button on the right. Even zippers in pants and jackets sometimes follow the same pattern.

But why does clothing fasten differently depending on whether it’s made for men or women? Fashion researchers and historians like us have wondered about this gender difference. The answer has a lot to do with tradition, history and the way clothes were made long ago. Even small details, like a zipper, can tell a story about the past.

Clothing is full of hidden history

When people look at clothes today, they often think about colors, comfort or style. But clothing is also part of what historians call material culture: all the objects people use every day. Examining the material culture of the past can reveal how people lived, worked and thought in earlier times.

Fasteners like buttons and zippers aren’t just practical. They also follow design traditions that became connected to gender over hundreds of years.

One of the most common explanations for why male and female garments have their buttons on opposite sides comes from European fashion history. A long time ago, wealthy women from the nobility often wore complicated dresses with buttons and fasteners – so complicated that they needed help getting dressed.

Some historians believe buttons were placed in a way that made it easier for a servant to fasten the clothing, reflecting class distinctions.

About 90% of people are right-handed. When a maid stood directly facing a noblewoman to dress her, buttons on the wearer’s left side were lined up perfectly for the maid to use her dominant right hand to fit them into the buttonholes. If you try buttoning a jacket onto a friend or a stuffed animal while facing them, you will see exactly why this layout made the maid’s job so much easier.

Men, on the other hand, usually dressed themselves. So shirts, trousers and uniforms were designed with fastenings that were easy for the wearer to manage himself – meaning buttons on the right side for a wearer to use his own right hand to fasten.

Men’s clothing was shaped by everyday practicality and function.

For example, some historians point to military traditions as a possible influence on button placement. Men often wore swords on their left side and drew them with their right hand. The direction jackets, shirts and trousers closed up may have helped prevent fabric from getting caught and in the way.

Fashion habits are hard to change

Once clothing started being made in factories in the early-19th century, brands needed consistent designs. Factories work best when patterns are standardized – so the button traditions stayed in place, even when people forgot how they started.

As zippers gained popularity in the early 1900s, clothing companies just stuck with the same customs about how men’s and women’s garments were supposed to close. Instead of creating brand-new rules, many manufacturers simply kept the same patterns they had used for buttons. So zippers often ended up following the same “direction” as older garment closures.

Today, more brands are making unisex and gender-neutral clothing meant for anyone, and many designers no longer follow the old left-side/right-side rule. It’s just a fashion tradition – there’s no reason zippers and buttons need to go on different sides for men versus women.

It is now more acceptable to break the old rules about which side buttons or zippers should go on. If you make your own clothes, you can put closures – whether buttons, zippers, snaps, ties, Velcro or even something new you invent yourself – wherever you want!

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The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.