As a curly haired scientist I was interested in this question. I didn’t know the answer though, so I had to read up a little bit. I guess there are differences in the hair structures and follicles that can cause curly vs straight hair. But I actually ended up being more interested in why there are two types at all. It turns out (at least a theory is) that original humans were mostly curly haired to better protect the head from sunlight, since they lived near the equator. As humans moved away from the equator, certain groups developed straight hair in order to get more sunlight on their skin. So nowadays both sets of genes are around.
The same reason why we are all different: the answer is in our genes. Some people have the curly hair gene and some have the straight hair gene. I didn’t know why but Dan has explained this above, so I’ve learned something new today! Curly hair tends to have flatter follicles and less smooth cuticles than straight hair. My hairdresser once told me that your hair type can change every so many years. Weirdly my hair has started to become wavy (I’ve always had super straight hair)!
In terms of mechanics, hair follicles may be round to produce straight hair, or oval. Oval hair follicles will produce spiral shaped strands… aka curly hair!
Comments