When you consider the structure of African/Black hair as compared to other, straight hair types, you may wonder why or how our hair developed into a kinky, coily pattern.  Currently the prevailing theory is one that has to deal with Adaptation.

Adaptation is a term that describes how African/Black hair has developed over time. Anthropologists believe that due to the high temperatures found throughout the continent of Africa, African hair has adapted to protect the scalp from the harmful rays of the sun. As a result, our hair appears kinky and usually forms tight masses of coarse hair.  Whether or not this theory is true...hmm...your guess is as good as mine.

Some say that African/Black hair is fragile.  In reality, it just has to be cared for differently.  See, every twist in African/Black hair represents a breaking point. Thus, individuals with curlier hair usually suffer because their hairs' shorter, more elliptical pattern is more susceptible to tangling, knotting and breakage relative to other hair types.

If you're the type who aggressively styles, combs, brushes or manipulates your hair, then you may unknowingly be putting stress on the various points of curvature.  Think of it this way, with straight hair you can move a comb through in one smooth motion because there aren't any bumps/curls to disrupt the action.

With Nappy, kinky, curly, coily... hair, each curl/kink is like a speed bump.  Comb too quickly and you can literally hear your hair breaking and ripping.  Comb slowly and you'll eventually meet an impasse.  This is why when you comb Natural black hair, it's a good idea to gradually work your way to the ends by inserting and reinserting the comb rather than attempting to comb in one motion.

Despite this adaptation, African/Black hair is almost chemically identical to other hair types. What makes African/Black hair different from Caucasoid or Asian hair is the bonding and wave pattern. Bonding refers to the structure of our hair and as above stated, the tighter the bond, the curlier and more fragile the hair.

The primary bonds found in our hair are hydrogen and polypeptides.  Hydrogen breaks down in the presence of water and then reforms in its absence.  This is what accounts for our hair flexibility.  This is why your hair stretches in humid environments or when wet.

Polypeptides found in Keratin which comprises roughly 88% of hair accounts for our hairs strength.  These bonds are more difficult to break and require the addition of a strong base (remember acids and bases from chemistry?) to be destroyed.  What is a strong base?  A Relaxer.  When you relax your hair, you destroy polypeptide bonds.  Thing is, once these bonds are destroyed, unlike hydrogen, they can never be repaired...they are forever altered.  This is why in order to return your hair to its natural state, you gotta cut off the relaxed ends.

Despite Ethnic Differences, the Structure of Hair is the Same
Cuticle: Outer layer of the hair. It is made up of a single layer of scales which Interlock with the cells of the hair's inner root sheath to firmly anchor it in the follicle.

Cortex: The middle layer. It is composed of keratinized cells which are tightly bound around one another. These fibril bands provide the hair with elasticity and strength and are very susceptible to chemicals and as a result can easily be damaged by dyes and relaxers.

Melanin is contained in the cortex and is the substance that determines the color of our hair and skin. The more melanin, the darker the pigmentation.

Follicle: This is the name for hair before it emerges from the skin. Follicles are composed of many elements including carbon, hydrogen and oxygen. Therefore a healthy flow of these elements can greatly improve the hairs' condition and appearance once it emerges.

Medulla: The medulla consists of large, loosely connected cells with intracellular air spaces. By reflecting light these air spaces determine the sheen and color Tones of the hair.

Sebaceous/Sudoniferous Glands: Attached to the hair follicle are the sebaceous (oil) and the sudoriferous (sweat) glands. The sebaceous glands produce waste by opening and closing continuously to release a waxy Sebum oil into the hair follicle and onto the scalp. The sudoriferous glands contain many small structures with porous openings leading to the skin. They produce substances which dry on the skin including salts, acids, water secretion and bacteria. If not completely dissolved and effectively removed from the scalp, they can help cause severe itching and dandruff.