The morphology of hair is directly controlled by the gene(s) which is the structural and functional unit of heredity. Although different racial groups share some common hair characteristics but due to diversity in gene pool hair of every individual varies in many traits. The generalities of hair characters are as follows:

• The Caucasians people possess highest number of hairs on their head with an average of two hundred hairs per centimeter, although the morphology of their hair thickness differs in most of the cases.
• Asians are having the thickest and coarsest hair on their head with an average density of hundred and fifty hairs per square centimeter.
• The thinnest and finest hair belongs to African Americans but it appears thicker more than that of Caucasian or Asian hair due to its matted nature. The average density is hundred and thirty hairs per square centimeter.

The three above mentioned examples clearly indicates that the morphological difference of hairs are strongly influenced by ethnicity and race and allow us to understand why people are not equal with respect hair. Due this divergent pattern of evolution of hair, lot of questions can arise in your mind regarding the relation between the ethnicity and the type of hair you posses but the limited space of this book resist us to go into the details. A deep relationship exists between this specialized organ called hair and the surrounding environment. For example, the African people have dark skin acting as a shield against Sorong sunlight and sun burns while the kinky hair acts as a good insulator and protect from sun to keep the body cool.

Some unexplained features of hairs still exists in different races when it comes to the comparison between the straight, lower density hair of Asians to the high density ones of Caucasians of North Europeans.

• Caucasian hair: Caucasians possess the highest number of hairs on scalp and the average density is 200 hairs per square centimeter. Normally 100,000 follicles on the scalp producing thicker terminal hairs is an important sign of a healthy Caucasian person. The production of fine, vellus hair scattered around the body is controlled by five million non-clap follicles as compared to the Caucasians. The dense nature of hair distribution makes the scalp of a Caucasian less visible and adds to the thickness of the hair in comparison to the Asians and Africans.   
• Asian hair: As compared to Caucasian the Asian scalp contains fewer hairs having an average of 140 to 160 hairs per square centimeter. A normal Asian posses near about 80,000 follicles. It tends to be straight with a low density in comparison to the curly or wavy and high dense Caucasian hairs. Due to its straight appearance the Asian hair does not cover well but the coarse and thick nature often compensate this.  
• African/African American hair:  The hairs belong to this group has the lowest density of distribution ranged between 120-140 hairs per square centimeter. The normal disease free scalp of this race posses 60,000 follicles. The morphological appearance is fine in some cases and kinkier in other. Due to sticky nature sometimes the hairs appeared highly dense in their distribution which is not the actual scenario. The dark skin complexion of Africans obscures the lower density for low contrast between skin color and hair.

External Resources

• Ethnic Hair Care