Hair Properties and Ethnicity

Natural hair types, colors, and textures are the result of the genes passed down from our ancestors. Scientists have identified three main races that influence hair types today: Mongoloid, Caucasoid, and Afroid.

• Mongoloid: Mongoloid hair originated with people from the Orient. It is very straight, coarse, and black in color. Perfectly straight keratin bundles and a round hair shaft account for the thick, straight texture. 
• Caucasoid: Caucasoid hair is more varied in appearance, since Caucasian ancestors range from fair-skinned people of northern Europe all the way down to India. Caucasoid hair ranges from the palest blonde to the darkest black, as well as wavy, straight, curly, thick, or thin. An oval hair shaft with straight or wavy keratin bundles may account for the variety of Caucasoid hair.
• Afroid: African hair comes in varying degrees of black and brown coils. The hair shaft may be oval and the cuticle sharply kinked at the edges. African hair can be dry and easily damaged due to its twisted structure and inability for sebum to easily lubricate the hair shaft.

All hair twists as it grows, and scientists believe it is the number of twists that determines how curly it will be. Scientists have found that some Afroid hair has 12 times as many twists per centimetre as some Caucasoid hair.¹

Hair gets its shape depending on the shape of the hair follicle and the opening to the scalp or skin. The final shape of the hair follicle occurs as the keratin hardens and both disulphide and hydrogen bonds hold it in place.

Disulphide Bonds: As discussed earlier, disulphide bonds are extremely strong and give hair their permanent shape. These bonds can only be broken and hair texture changed with strong chemicals like perms and relaxers.

Hydrogen Bonds: Hydrogen bonds also exist within keratin and are much weaker than disulphide bonds. They give hair flexibility and can be easily broken with water. The hydrogen bonds reform themselves as they dry, allowing for temporary hair styling with rollers and other methods.

Whether hair appears dense or sparse on the head usually depends on two factors: how many hairs a person has and how thick the diameter of the hair shaft is. The number of terminal hair-shafts on a head ranges from 100,000 to 150,000. Natural redheads tend to have the least amount of hair while blondes have the most.

Interestingly, National Geographic reports that in our world of 7 billion people, the most “typical” person is a 28-year old Han Chinese male.¹ That means that the most typical hair type in the world today is straight, black, and Asian. By 2030, however, the most typical human – and hair type – will be Indian.

Natgeo.com, Have You Seen Him? http://www.thelifefiles.com/2011/03/05/have-you-seen-him/

P&G Beauty & Grooming, Hair Types, http://www.pgbeautygroomingscience.com/hair-types.html