What makes hair Curly?

If you’re like me and have curly hair, some days it is nearly impossible to get your hair to stay still.  Humidity is my worst nightmare and some days it is nearly impossible to do anything to it.  This got me to thinking, what makes hair curly?

In article published in Time Magazine, they say that curly hair is determined by physics.  In a study published in the Journal Physical Review Letters explained why curly hair can be hard to control at times. 

The investigation concluded that, “the biggest variale curly hair has to reckon with is weight.”  This means that the longer the hair grows, the more of a burden hair becomes.  Eventually, the strand will become too heavy and topple over.  In opposition, straight hair is more 2-D and really only moves in 2 dimensions. 

If you have curly hair and it is shorter, it creates more of a 3-D helix.  This means that the strands grow, “up, down, swooping in an angles, doubling back on itself.” If the hair is longer than the head or beyond, the researchers call it’s called a 3-D local helix, which is more complex. 

Curly hair can be attributed to genetics.  In a 2009 study conducted it was determined that, “a heritability of between 85 and 95 percent.”  This research showed that the way a curl bends depends on its follicle.  If a follicle is asymmetrical the hair that is produced is more likely to curl.  If the follicle is symmetrical, then the hair grows straight. 

This study also showed that even if you are born with symmetrical follicles, it is still possible to have curly hair.  The scientists who conducted this study, determined that, “a cellular receptor called EGFR clusters on the outer root sheath of a follicle and appears to regulate the growth of hair.” 

The study can be seen here


Although scientists can look at the physics and theoretics of curly hair in many studies, curly haired people like myself look at the problem of criss less theoretical.  There can be theories and studies conducted on curly hair that looks at the algorithms behind it, but for the most part everyday people will continue to try to tame the mane with styling products.

Works Cited

Time Article

Popular Science

5 thoughts on “What makes hair Curly?

  1. Julie Ramioulle

    I really love when I find blog posts that I can so easily relate too. It makes learning about what you have researched and analyzed that more interesting! While the source you sited for your study isn’t necessarily the most reliable, there are plenty out there that prove to be. Such this study here, where a similar objective of what type of hair follicles you’re born with doesn’t mean that’s the kind of hair it’ll turn out to be. While I was researching that study it lead me to question whether or not you can predict what type of hair someone will have? Here’s another study I found aimed just at that.

  2. Samantha Marie Grillo

    I was intrigued when I saw the title of this blog post because I have curly hair, and it was interesting to read about how genetics can affect the curliness of your hair. I also have trouble with my hair when it is humid or raining out; those are the days when I ditch my straightener and just embrace the curls.

    Here is the link to a picture of Monica from Friends, who also experiences that curly hair struggle in the humidity: http://www2.pictures.zimbio.com/mp/fvQkGyBftq-x.jpg

  3. Shannon Elizabeth Kress

    I am with you on the fact that humidity is my worst nightmare! Here it talks about how the hydrogen bonds react with the keratin in our hair. It’s really interesting! You should take a look.

  4. Anthony Joseph Martin

    One question I had while reading was how does the humidity affect hair? After reading what you said about the weight of the hair causing the helix shape, I was guessing that it was the moisture clinging to the hair and weighing it down. Also what types of algorithm equal curly hair?

  5. John Michael Federici

    In your conclusion, you mentioned how “curly haired people like myself look at the problem of criss less theoretical. Can other areas of mental traits be affiliated with these physical? For instance, can eye color determine how an individual reacts to a certain situation?

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