Straight or curly hair!

Find out what determines the structure of straight and curly hair.
Why do some people’s hair curl while others have straight hair?
If you’re wondering, the answer may surprise you.
It’s all in the genes: hair structure is written into the genetic code.

Many people express their personality through their hair, for example by straightening it.
However, the effects are not permanent, as nature itself decides whether the hair is straight or curly.

Hair structure is in the genes

Straight or curly hair is a trait written into the genetic code.
Australian scientists at the Queensland Medical Research Institute have determined which gene is responsible for hair structure, calling it trichohyalin.
According to them, hair becomes curly when there is an imbalance of amino acids in this gene.

It’s important to note that hair type is a trait that is not only passed down in a straight line.
This means that a child can have curly hair even if both parents have straight hair.

The cross-section of a hair tells the truth

It’s easy to see the differences between straight, slightly wavy and very curly hair by performing microscopic examinations of the structure of a single strand.
Under high magnification, straight hair has a round cross-section.
Curly hair has a flattened, elliptical cross-section when examined under the microscope.

The straighter and stiffer the hair, the rounder the cross-section.
The more twisted the strands, the flatter the cross-section, with the edges curling into a twisted shape in the case of severe twisting.

Straight or curly, find out which hair type you have

How hair types affect the structure of your hair is, in theory, immediately obvious.
Nevertheless, it’s worth checking the curvature of your hair to make sure it’s well cared for.

A simple test will help:

• Draw a circle on a sheet of paper, perhaps in the shape of the bottom of a cup.
• Pull a hair from the center of your head until it is about 15 cm long.
• Wet the hair strand in water and leave it to dry.

Once dry, check the part of the circle occupied by the hair: if half the circle is occupied, the hair is straight; if at least three-quarters of the circle is occupied, the hair is curly.

Relaxers and perms have no lasting effect

Since hair structure is determined solely by genetics, it is difficult to achieve permanent results with treatments such as keratin straightening or perming.
These treatments modify the structure of the bonds within the hair, but the results don’t last long.

• Also read: what is your hair type A, B or C?

• Also read: How porous is my hair?

The downside is that they also have a negative effect on hair, making it weaker.
So there’s no choice but to make do with straight or curly hair.
They all have their charms, and all it takes is professional maintenance to keep your hair healthy and shiny.