Types of Hair
Hair science recognizes three categories of hair: African, Caucasoid and Asian. All the hair types possess different properties and one hair type is not superior to others.
The hair shaft of African hair is oval on cross section (in contrast the round shafts of Caucasians and Asians). This configuration allows the hair shaft to twist on itself and form the characteristic kinky or curly hair. African hair is almost flat or ribbon like in shape, twisting, turning, and bending as it grows. At every twist and turn, the hair tends to be thinner and therefore susceptible to breakage at each of these points along the hair shaft. Because of its shape, the cuticles on African hair tend to be raised, and do not lay flat against the hair shaft. As a result, African hair absorbs light and does not reflect it.
This is the explanation why African hair does not shine. Raised cuticles also act like opened doors, causing African hair to be very porous. It is able to absorb moisture like that of a sponge but it has a hard time retaining it; hence, African hair is inherently dry. Raised cuticles also causes African hair to feel coarse to the touch, rub and catch easily on one another leading tangles, knots and even more susceptible to damage and breakage if it isn’t cared for properly. Proper care include usage of water based moisturizers, gentle combing from the root, and gentle hair care practices. African hair although strong and tough in appearance is in fact very fragile prone to breakage. African hair can be divided into two distinct, but overlapping types; one that is wiry and tightly kinked and other that has a looser, more wavy kink with a softer feel. Black hair is not necessarily truly black, but rather a combination of black and red pigment giving rise to shades from almost true black through to dark brown and auburn (the latter in less than 10 per cent)
Caucasoid hair is more oval in shape. The more oval the hair, the more likely it is to be wavy. The more round the hair, the more likely it is to be straight. The cuticles on caucasoid hair tend to lay flat, allowing the hair to retain moisture, reflect light and shine. Caucasian hair varies hugely due to the mix in ancestry – often a wide combination of genetic influences. It is oval in cross section, tends to be fine to medium in diameter, and varies from straight to wavy – curly. It is also the only ethnic group with large variations in color, from white blond to browns, reds and black. Amongst Caucasians, over 70% have fine textured hair. Generally blonds have the finest hair texture. Darker shades tend to be coarser, and redheads have the coarsest hair.
The hair of Asians is almost perfectly round resulting in bone straight hair. The cuticles lay flat, reflects light, is very strong and holds moisture. In general, Asian hair is characterized by being:
- High skin/hair color contrast
- Smaller follicular units
- Lower density
Asian hair is round in cross section, and therefore is usually straight or slightly wavy. It is black or dark brown, and has the thickest diameter and the greatest strength of the ethnic groups. Asian hair also has the capacity to grow to a greater length than other hair types.
Krause, K; Foitzik, K (2006). "Biology of the Hair Follicle: The Basics". Seminars in Cutaneous Medicine and Surgery
Sabah, NH (1974). "Controlled stimulation of hair follicle receptors.". Journal of applied physiology (2): 256–7. PMID 4811387