man doing laundry covering nose for smelly sock at laundry room


GOTHENBURG, Sweden — Have you ever thrown a barely worn shirt into the laundry just because you wore it once? You’re not alone. In fact, a new study explains that our obsession with cleanliness and sheer hatred of “disgust” are evolutionary phenomena passed down from generation to generation. At first glance, it sounds like a pretty good thing, right? Who wants to stink all day or wear smelly clothes? However, researchers in Sweden say people are actually overdoing it when it comes to cleaning!

A study by a team at Chalmers University of Technology in Sweden claims that people who go overboard with washing their clothes (especially in a washing machine) might be doing more harm than good — not just to their garments but also to the environment. Their research sheds light on the psychological factors driving our laundry habits, and the results are eye-opening. It turns out that our fear of being perceived as dirty often trumps our desire to be environmentally friendly, even for those who support “green” causes.

The Dirty Truth About Clean Clothes

Let’s face it: we’re washing our clothes more than ever before. With easier access to washing machines and advances in technology, tossing our clothes into the wash has become second nature. However, researchers say this convenience comes at a cost.

The study published in PLoS ONE finds that 16% to 35% of global microplastic emissions come from washing synthetic fibers. That means every time you wash your favorite polyester shirt, you could be releasing up to 700,000 microplastic fibers into the water system. These tiny particles eventually make their way into our oceans, accumulating on the seabed and entering the food chain.

It’s not just microplastics people need to worry about, the researchers say. Detergents contribute to water pollution, and the energy and water used in washing machines add to our environmental footprint.

The Psychology of Laundry

So, why do we keep washing our clothes so frequently, even when we know it’s not great for the environment? This is where the Chalmers study gets interesting. The researchers, led by doctoral student Erik Klint, looked at two main factors influencing our laundry behavior:

  1. Environmental identity: How strongly we identify with being environmentally conscious.
  2. Disgust sensitivity: How easily we feel disgusted by things we perceive as unclean.
Body odor
(© Satjawat –

You might think that people with a strong environmental identity would wash their clothes less often. However, the study found that disgust sensitivity wins out, regardless of how eco-friendly a person considers themselves to be.

“We humans are constantly faced with different goal conflicts. In this case, there is a conflict between the desire to reduce one’s washing to save the environment and the fear of being perceived as a disgusting person with unclean clothes. Disgust is a strong psychological and social driving force,” Klint explains in a media release.

Evolution vs. Environment

Why does disgust have such a powerful influence on our behavior? It turns out it’s hardwired into our brains. Disgust is an emotion that evolved to protect us from potential sources of disease or harmful substances. It’s also closely tied to feelings of shame, which can affect our social standing.

“We humans don’t want to do things that risk challenging our position in the group – such as being associated with a person who doesn’t take care of their hygiene,” Klint notes.

So, when it comes to deciding whether to wear that shirt one more time or toss it in the laundry, our ancient instincts often overrule our modern environmental concerns. Simply put, it doesn’t matter how eco-friendly you are — your instincts say go wash your smelly clothes.

Rethinking What ‘Clean’ Means

The study’s findings suggest that current campaigns to promote eco-friendly laundry habits are missing the mark. Simply telling people to wash less often isn’t an effective or popular message for the general public.

Instead, Klint wants society to ask a different question: “How do we get people to generate less laundry, specifically laundry that needs to be cleaned by a washing machine?”

Some suggestions from the study include:

  • Encouraging people to wear clothes multiple times before washing.
  • Promoting alternative cleaning methods like airing out clothes or spot-cleaning stains.
  • Highlighting the economic benefits of washing less, such as clothes lasting longer.

As washing machines become more common worldwide (an estimated 80% of households in 18 countries surveyed had access to one in 2024), researchers say addressing our laundry habits becomes increasingly crucial for environmental protection.

“The direct result we hope for is to contribute to reduced environmental impact from laundry, but it is possible that the research can be generalized to other areas where behavior and technology interact,” says study co-author Gregory Peters, Professor of Quantitative Sustainability Assessment at Chalmers.

About Chris Melore

Chris Melore has been a writer, researcher, editor, and producer in the New York-area since 2006. He won a local Emmy award for his work in sports television in 2011.

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1 Comment

  1. Marvin L McConoughey says:

    A great advantage of not washing your clothes is that after some time, they stand up by themselves, being too stiff to collapse when taken off. Also, when worn, they serve as a light armor protecting one’s fragile self from arrows, bullets, etc..