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Defining your ethnic hair type

Human hair – which grows everywhere on the body except the palms of the hands, soles of the feet, eyelids and lips – can differ markedly in texture and colour. Yet all human hair has similar functions. Scalp and body hair is believed to keep us warm by preserving heat. It cushions our heads, giving some protection against injury. The hair inside our nose and ears and around our eyes protects against dust and germs, while eyebrows and eyelashes protect our eyes against sweat, harsh light and tiny particles. Armpit hair helps to reduce friction.

Unlike other mammals, humans do not moult, because our hair follicles are all at different stages of the growth cycle at any given time. (If they had all been synchronized, everybody would have gone bald from time to time.) Nevertheless, we do shed our hair at a rate of 50 to 80 scalp hairs a day (the figure of 100 hairs a day, often quoted as the average daily hair loss, is now believed to be exaggerated). As we’ll see later, factors like changing hormone levels, diet and medication can influence the hair-loss rate quite drastically.

Your hair type is determined by your genetic make-up; you can change your look, but not your hair’s inherent characteristics.

In a class of its own

Human hair can be coarse and black, fair and fine, straight and thick, wavy or kinky, but despite the different variations in colour and texture, it is generally classified into three ethnic types: Caucasian, Asian and African.

Although the hair of most Scandinavians differs markedly from that of a South American or Spaniard, they all have hair that can be classified as Caucasian. The same goes for Indonesian and Japanese hair – both are Asian hair types. Typical Caribbean hair is classified as African hair. Even though there are variations within hair types, the three main ethnic classifications have very distinctive characteristics.

Your hair type is determined by your genetic make-up and although there are ways to temporarily change its look, you can never change its inherent characteristics.

CHANGING YOUR LOOK

Unlike facial features or body shape, hair is relatively easy to change, and the hair products industry is booming, with industry players spending millions on research each year. A crucial element to offering consumers what they want and need is a thorough understanding of hair types.

The chemical compositions of the three ethnic hair types, and the molecular structure of the keratin therein, are all similar, but the hair shafts differ. While there is some understanding of the reasons for this, research into the differences continues.

African hair is dark and tightly curled; Asian hair tends to be straight, coarse, dark and thick, while Caucasian hair ranges from fine and straight to relatively thick and wavy, and has the greatest variation in colour. The differences between the hair types, according to international hair products company Wella, centre on its longitudinal and cross-sectional shape, thickness, ellipticity (whether the hair is ‘round’ or ‘flat’) and colour.

HOW HAIR TYPES DIFFER IN SHAPE

Asian hair: This hair type has an approximately round shape.

Caucasian: This hair type has an oval shape.

African: This hair type is extremely oval, almost flat.

An example of typical Caucasian, African and Asian hair types. Caucasian hair has the greatest variation in texture and colour.

Texture

A strand of Caucasian hair has an average thickness of 0.07mm (3in) and, seen in cross section, has an oval shape. Coarser Asian hair, about 0.09mm (3.5in) thick, has an approximately round shape, while African hair, ranging between 0.04 (1.6in) and 0.12mm (5in) in thickness, is ex- tremely oval (nearly ‘flat’).

It is generally no longer believed that the shape of a curly hair is caused by a curved hair follicle. The follicles of curly hair are, in fact, straight. Further evidence that follicle shape has nothing to do with the curliness or straightness of hair is that some types of medication may cause curly hair to suddenly go straight, without any change to the follicle. All hair – even straight Asian hair – twists as it grows, but the more it twists, the curlier it is. African hair is the most fragile of the three hair types.

Hair product company L’Oréal’s institute for ethnic hair and skin research considers the particular structure of African hair to be the reason for this. As mentioned, each African hair shaft has a distinct oval – almost flat – shape. The outer cuticle scales protecting each hair are thinner in the areas where the oval-shaped hair shaft is thinnest. As a result, these thin parts of the cuticle break easily, exposing the inner cortex of the hair. Once the more vulnerable cortex is no longer protected it then also breaks easily. In addition, the chemical composition of a part of the cuticle, prone to microscopic cracks, causes African hair to have weak mechanical resistance, according to L’Oréal scientists.

The weak points along the hair shaft and the spiral twists make African hair quite difficult to groom, and certainly more difficult to comb than straight Caucasian hair. It is also more brittle, splits more easily and has a lower moisture content. To straighten such hair, heavy-duty chemicals are needed, and damage is bound to occur to the hair structure.

Asian hair is thicker than Caucasian hair and has about 10 layers of cuticle cells, making it stronger and stiffer with more body. Asian hair contains a medulla filled with plenty of dark pigment, thought to contribute to their shine and high moisture content. Asian hair also tends to grow longer than African and Caucasian hair as it has the longest growth cycle of the three hair types: up to nine years. In addition it grows faster than African and Caucasian hair – about 1.3cm (0.5in) per month, compared to the 1.2cm (0.4in) and 0.9cm (3.5in) of the two other hair types respectively. On average, Asians also shed fewer hairs a day than Africans or Caucasians, and Asian men tend to experience less balding (Caucasians have the highest incidence of male-pattern baldness).

The characteristics of hair

Whatever your hair type, all hair shares certain properties:

■ It is elastic because of the coiled structure of the keratin, and this elasticity increases when hair is wet. Because of its elasticity, a healthy hair can stretch up to 20 or 30 per cent of its length before it breaks.

■ Hair swells (gets thicker) if it is soaked in water, as the water enters the air spaces between the fibres of the cortex. A hair in good condition can, in fact, absorb about 30 per cent of its own weight in water.

■ Hair is porous, and liquids can pass between the outer cuticle scales into the cortex. Porosity increases if the cuticle is damaged or if the cuticle scales are lifted through heat, steam or chemical treatments. Sebum and certain conditioning creams or lacquers can decrease the porosity.

■ Hair is hygroscopic and absorbs moisture from the air. This explains why the same head of hair can behave very differently in dry and humid conditions. When it is humid, hair absorbs a lot more moisture and tends to become frizzy, whereas it tends to be straight in a dry climate. The normal moisture content of hair is about 10 per cent of its weight, but this can increase to 30 per cent.

Greying also starts later. However, there is evidence that Asian women over 45 tend to experience more overall thinning of hair than their Caucasian and African counterparts, and because Asian hair is thicker and often longer than other hair types it tends to lose more moisture, which leads to dryness and split ends.

About 70 per cent of Caucasians have finely textured hair, and 30 per cent have medium-textured or coarse hair. Colour and texture appear to be linked: blondes tend to have the finest hair, while redheads tend to have the coarsest. Although Asian hair is thicker, Caucasian hair has the highest density of the three hair types.

Hair can be fine, medium-textured or coarse. Fine hair always tends to lack volume, while medium hair is often quite easy to handle, strong and elastic. Coarse hair brings its own problems: it is abundant, but can be heavy, frizzy and difficult to control. You may find that you have fine hair in your hairline and on your temples, while the rest of your hair is medium or coarse.

A QUESTION OF OIL AND MOISTURE

Whether you have dry, oily, normal or combination hair depends on how much oil your sebaceous glands produce, and how you treat your hair. It is impossible to stop your sebaceous glands producing grease, and it is also an old wives‘ tale that oil production is very much affected by your diet. Eating too many chocolates or greasy food may well lead to weight gain, but it will not make your hair oilier! While you cannot change your genetics, understanding your hair type and treating it accordingly can help you have a healthy, good-looking head of hair.

Oily hair

If your sebaceous glands produce too much sebum, your scalp and hair tend to be oily and your hair may even become lank and greasy only a few hours after you have washed it. You will therefore need to wash it more often than someone with normal hair. Contrary to popular belief, frequent washing does not exacerbate the oil problem. If you tend to have greasy hair, do not touch it often or run your fingers through it constantly, as this can make hair appear greasy quicker. Too much brushing also helps to distribute oil. While some experts advise using a shampoo formulated for oily hair, others believe that it’s better to wash your hair often with a mild shampoo. Apply conditioner only to the ends. A good tip is to use hairspray after you have styled your hair. This keeps it out of your face and stops you from touching it frequently.

Heat from a hair-dryer can be damaging to hair. Try to cut down on blow-drying, particularly if your hair tends to be dry and brittle.

Dry hair

Dry hair – which literally contains too little moisture – can be caused by a variety of factors: naturally it is the result of sebaceous glands producing too little sebum, but chemical treatments, frequent washing, harsh sunlight, wind, overuse of hair-dryers and hair age (hair that has not been cut for a long time) can also cause dry, brittle hair. This hair type can lack shine, feel rough and break, and tangle easily. Use a shampoo for dry hair and always follow a wash with conditioner. Try to cut down on blow-drying and avoid chemical treatments such as bleaching, straightening and perming. A regular hot-oil treatment may help, but the better solution for dry and split ends is to cut them off.

Normal hair

Normal hair is neither too dry nor too oily, feels soft and healthy and does not tangle easily. This type of hair is easy to manage and style, and usually has not been coloured, straightened or permed. The sebaceous glands tend to produce just the right amount of oil, but a healthy lifestyle, good grooming habits and sensible treatment of your hair also help. Wash your hair regularly, but not every day, and use a light conditioner.

Combination hair

If your roots and scalp are oily, but your hair ends are dry, you have combination hair. This can be the result of treatments which strip the hair of moisture. Harsh sunlight and long hair that has not been cut for some time can also lead to combination hair. When washing your hair, concentrate on the scalp area and always use moisturizing conditioner on the ends. Bear in mind the guidelines for both oily and dry hair if you have combination hair: do not touch your hair too much, and go easy on the hair-dryer and styling tools.

The only cure for split ends is to cut them off, but conditioner can help to prevent further damage and improve the feel of your hair.