Natural afro-hair

Afro-textured hair is the natural hair texture of certain populations in Africa, the African diaspora, Oceania and Asia. Each strand of this hair type grows in a tiny, spring-like helix shape. The overall effect is such that, compared to straight, wavy or curly hair, afro-textured hair appears denser.

In many post-Columbian, Western societies, adjectives such as "wooly", "kinky", "nappy", or "spiralled" have frequently been used to describe natural afro-textured hair. More recently, however, it has become common in some circles to apply numerical grading systems to human hair types.

One popular version of these systems classifies afro-textured hair as 'type 4' (straight hair is type 1, wavy type 2, and curly is type 3, with the letters A, B, and C used to indicate the degree of coil variation within each type), with the subcategory of type 4C being most exemplary of this hair type (Walker, 1997). However, afro-textured hair is often difficult to categorize because of the many different variations among individuals. Those variations include pattern (mainly tight coils), pattern size (watch spring to chalk), density (sparse to dense), strand diameter (fine, medium, coarse), and feel (cottony, wooly, spongy).

The chart below is the most commonly used chart to help determine hair types:

Different ethnic groups have observable differences in the structure, density, and growth rate of hair. With regard to structure, all human hair has the same basic chemical composition in terms of keratin protein content. Franbourg et al. have found that Black hair may differ in the distribution of lipids throughout the hair shaft. Classical afro-textured hair has been found to be not as densely concentrated on the scalp as other follical types. Specifically, the average density of afro-textured hair was found to be approximately 190 hairs per square centimeter. This was significantly lower than that of Caucasian hair, which, on average, has approximately 227 hairs per square centimeter.

Loussourarn found that afro-textured hair grows at an average rate of approximately 256 micrometers per day, whereas Caucasian hair grows at approximately 396 micrometers per day. In addition, due to a phenomenon called 'shrinkage', afro-textured hair that is a given length when stretched straight can appear much shorter when allowed to naturally coil. Shrinkage is most evident when afro-hair is (or has recently been) wet. The more coiled the hair texture, the higher its shrinkage.

An individual hair's shape is never completely circular. The cross-section of a hair is an ellipse, which can tend towards a circle or be distinctly flattened. Asiatic heads of straight hair are formed from almost-round hairs, and Caucasian hair's cross sections form oval shapes. Afro-textured hair has a flattened cross-section and is finer, and its ringlets can form tight circles with diameters of only a few millimeters. In humans worldwide, Asiatic hair is the most common, whereas afro-textured hair is the least common. This is because the former hair texture is typical of the large populations inhabiting East Asia as well as the indigenous peoples of the Americas.

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Wikipedia