Twisted hairs - make curly hair?

**cmg** · November 13th, 2011, 08:07 PM

Hi everyone! I snipped this quote from another thread, hope you don't mind, ktani:

Originally Posted by ktani

(Quotation from
http://www.pgbeautygroomingscience.com/hair-types.html )

"All hair, even the apparently perfectly straight hair of Asian people, twists as it grows. The number of twists in a given length of hair determine how curly it is: the more twists there are, the curlier it will be. Some African hair has 12 times as many twists per centimetre as Caucasian hair."

I have been wondered about this. I have very twisted hair, but I always put that down to heat damage. I mean twists like "Turning torso" here. I am alittle skeptic about the statement this would affect the overall curliness, having had some poeples hairs under the microscope in my work. I recall at least two samples that were "perfectly straight" under the microscope, but they had (naturally) curly hair. It is not a big stretch to believe it's this way though. It could work like something of the "twisting a rope hard"-effect. Twist it hard enough, and it starts coiling up. But where is the fixed pressure on hair? Any opinions or thoughts on this?

**missdelarocha** · November 13th, 2011, 08:19 PM

That's very interesting, I agree with your rope reference but am still not sure, I suppose it makes sense but I don't think it's going to turn out to be fact.

ETA:
http://www.lifeslittlemysteries.com/...ir-curly-0255/
According to another site the amount of disulphide bonds is what causes curls, that might be what they're talking about (in the site linked above) when they say "Scientists once thought that the curliness of hair was determined by the individual hair shafts" though.

**dawnrader** · November 13th, 2011, 08:22 PM

The only fixed pressure i can think of that would be on hair would be gravity pulling it towards the centre of the earth. Certainly nothing to make it twist. As far as i was aware having curly hair was to do with abnormal hair follicles.

**CurlyCap** · November 13th, 2011, 08:35 PM

Originally Posted by dawnrader

As far as i was aware having curly hair was to do with abnormal hair follicles.

Not so much abnormal. Just different.

I've always liked this explanation, because it's something we've all done. I always wanted to try the part where you run your nails down a piece of straight hair, but I don't have anyone to ask. And collecting a straight hair is...creepy.

http://www.education.com/science-fair/article/curly/

**CurlyCap** · November 13th, 2011, 08:41 PM

Originally Posted by cmg

Twist it hard enough, and it starts coiling up.

I always wondered about this.

There are two ways to get super defined curls (not product based)in those of us with natural curls:

1. Doodles: Take a clump of hair and wrap it around your finger, like you're forming a spring out of your hair. Smooth the final product and slip your hair off your finger. Voila! instant perfect (and indestructible) curl.

2. TWISTING: Never understood this. I'm sure there's some physics to it. But if you take a clump near the scalp, smooth it so all the hairs line up, and then twist it moving the from the scalp down, you get a perfect sausage curl.

However, when I read that curly hair has more twists as it comes of out of the scalp, I'm always like "Duh. It's curling as it grows!" Maybe it's more complicated that than that though.

**cmg** · November 13th, 2011, 08:58 PM

I cinda subscribed to this theory, to some extent: "Scientists once thought that the curliness of hair was determined by the individual hair shafts" I find the sulfide bonds theory being alittle far fetched but not impossible. Fingernails that grow long usually curl too. The curl does not happen in the hair or should I say nail. Curvature is detectable as soon as the nail leaves the skin, indicating something happens already there. Have you seen theese meter-long nails? Some are really scary.

Somewhere I read also that curliness might be influenced by the angle in which it grows out of the skin. Many of my hairs grow in a low angle, making plucking eye brows difficult for example. Hmm...

**holothuroidea** · November 13th, 2011, 09:03 PM

I always thought that the curliness of the hair was due to the frequency of disulphide bonds in the protein that makes up the hair shaft.

What I've always wondered is why hair texture changes over time or after hormonal changes. My hair was 1a until I had my first baby and BOOM waves come out of nowhere. I'm not the only person this has happened to. Some people are born with curls and then they disappear after their first cut. Some people have wavy hair until puberty and it turns into ringlets.

So what exactly dictates the frequency of our disulphide bonds? Maybe there is more than one contributing factor to curly hair.

Very interesting topic, cmg!

**holothuroidea** · November 13th, 2011, 09:09 PM

Originally Posted by cmg

I find the sulfide bonds theory being alittle far fetched but not impossible.

I learned this in biochem (and can you believe I payed attention?

). It was not presented to me as a theory. We were learning about protein structures and what gives them their shape. When disulphide bonds came up the teacher said "this is why hair curls." And we all nodded and said "ah-ha."

Biochem teachers have been known to be wrong.

**missdelarocha** · November 14th, 2011, 03:53 AM

Originally Posted by cmg

The curl does not happen in the hair or should I say nail. Curvature is detectable as soon as the nail leaves the skin, indicating something happens already there. Have you seen theese meter-long nails? Some are really scary.

Yes haha I've seen them! It's interesting because the bend makes for appealing and strong nails but it doesn't occur to most people that eventually this would lead to curling. I wonder what mine would do, they're rather flat haha.

Originally Posted by cmg

Somewhere I read also that curliness might be influenced by the angle in which it grows out of the skin. Many of my hairs grow in a low angle, making plucking eye brows difficult for example. Hmm...

I wonder if eyebrows were able to grow longer would they would curl

? Though maybe they're round not oval and the follicle is actually at an angle, because according to another link posted the object wants to bend towards it's flatter side, which suggests one side of the single curly hair is flatter but not necessarily growing out from the follicle at an angle.

Weeeeerrrryyy intewesting.

**luxepiggy** · November 14th, 2011, 06:37 AM

Curly hair is characterized by asymmetric keratinization of the cortical cells - basically, the two sides of the hair are keratinized at slightly different rates. The hair curls in the direction of the slower growing side; the greater the asymmetry, the curlier the hair (http://onlinelibrary.wiley.com/doi/1...454.x/abstract)