The interesting reason why people with curly hair may have had an evolutionary advantage

Did you ever think your curly hair could be used as a source of protection?

woman with gray curly hair on a blue background
(Image credit: Getty Images)

You might have a love-hate relationship with your curls, but evolution has proved your curly hair could actually have been an evolutionary advantage, according to a recent study. 

If you have a naturally curly hairstyle, you know what a struggle it can sometimes be to keep your curls looking fresh every day. Between using diffusers (here's how to properly use a diffuser), trying to look up the most recent TikTok hacks for taking care of curls, and putting in product after product for curly hair, it can get exhausting trying to keep up with it. 

But, according to a recent study from Penn State University, curly hair is actually now believed to have been helpful to humans in regulating body temperature, and even minimized the need to sweat in order to stay cool. Additionally, hair texture, curly hair specifically, may have played a huge role in how the size of the human brain grew to its typical size over time. 

woman with curly hair on an orange background

(Image credit: Getty Images)

While conducting the study, the scientists used wigs and a mannequin that used electricity to mimic body heat, and from there, analyzed how different hair types affected the body temperature of the mannequin. 

The scientists used human hair wigs to examine how diverse hair textures affect heat gain from solar radiation. Then, they programmed the mannequin to maintain a constant temperature of 95 degrees Fahrenheit – similar to the average surface temperature of the skin, according to the National Institute of Health – and set it in a climate-controlled wind tunnel.

They shone lamps on the mannequins' heads to mimic solar radiation under various hair types - including straight, moderately curled, or tightly curled.

After conducting their studies, they conclusively found that, although all hair types reduced solar radiation to the scalp, tightly curled hair yielded the best protection from the sun’s heat - which, in turn, minimized the need to sweat to stay cool.

Tina Lasisi, who helped conduct the study as part of her doctoral dissertation at Penn State, weighed in, “Bipedal posture and a hairless body may have necessitated the development of scalp hair to minimize heat gain from solar radiation, particularly in [primates] with large brains," she said. 

In case you didn't know, bipedal posture is the typical upright posture humans use to walk on two legs. 

woman with curly hair

(Image credit: Getty Images)

From the studies conducted, it was concluded that scalp hair probably evolved as a way to reduce the amount of heat gained from solar radiation, which kept humans cool without the body having to lose electrolytes and use extra energy. So the next time you feel annoyed at your curly locks, just remember that, evolutionarily speaking, you're at a better advantage in the heat than most other people.

Madeline Merinuk
US Lifestyle News Writer

Madeline Merinuk is woman&home's US lifestyle news writer, covering celebrity, entertainment, fashion, and beauty news.

She graduated in 2021 with a B.A. in Journalism from Hofstra University, winning multiple student journalism awards, including a National Hearst Award, during her time there. After graduating, she worked at, the digital site for the Today Show, where she wrote pop culture news and interviewed big-name personalities like Emily Ratajkowski, Haley Lu Richardson, Emma Corrin, and more.

Her personal interests, in no particular order, are: cheese, Joni Mitchell, reading, hot yoga, traveling, having multiple chapsticks in every handbag at all times, and dancing to ABBA songs as if she were in the Mamma Mia movies.