Read about hair issues and cosmetic treatments in ‘Beauty: The Ultimate Cosmetic Makeover Guide. Book 2: Body, Teeth & Hair‘.
What makes head-hair attractive?
People of different cultures and different historical periods have viewed the hair that grows from the scalp in a wide range of ways. Hairstyles and fashions in hair colors come and go. The arrangement of one’s hair is often used to indicate one’s personal beliefs, age, sex, religion or social position.
It is often claimed that men prefer blond women. ‘Flaxen’ is the hair-color of beautiful princesses in fairytales, and a multitude of Hollywood actresses have been blond. Ten years after Charles Darwin published ‘On the Origin of Species’ in 1859, the great man began studying the sexual selection of blond hair in women, in readiness for his book ‘The Descent of Man and Selection in Relation to Sex’, which was later published in 1871. He was, however, unable to find enough data to support his theory that blond hair is sexually selected and abandoned his research.
Blond hair is more common during youth. The blond locks of children generally darken as they grow older, so if males really do prefer blond women, it might be because (prior to the ready availability of hydrogen peroxide), blond hair in females could be interpreted as a sign of youth, and thus reproductive fitness.
Blondness is not always perceived as desirable. In central Africa, for example, the birth of an albino baby arouses superstitious fear that can lead to infanticide.
More girls are born blond than boys. One study found that females whose hair remains naturally blond into adulthood are generally physically fitter.
Caucasian blondes generally have slightly higher estrogen levels than brunettes. They also tend to have other characteristics that indicate low levels of testosterone and are considered attractive by males, such as finer facial features, smaller noses and jaws, pointed chins, narrow shoulders, evenly-textured skin and sparse body hair, and childlike behavior such as liveliness and playfulness.
Blond hair in males is no indicator of estrogen levels as it is in females; nor is it a sign of fitness as it is in females. Furthermore, unlike men, women do not base their choice of mate on physical appearance to the degree that men do. This might explain why blondness, if it is an attractive trait, is generally judged to be desirable in women.
Abundant scalp hair can be viewed in a variety of ways, according to one’s cultural background.
‘In Australia, balding Aranda Aborigines once wore wigs made of emu feathers. Likewise, the Azande in Sudan wore wigs made of sponge. To grow long hair among the Ashanti in Nigeria made one suspect of contemplating murder, while in Brazil the Bororo people cut their hair as a sign of mourning.’
In most cultures, short hair signals restraint and discipline. Generally, the hair of prisoners, soldiers, and monks is short. Long hair tends to signify freedom and individualism. The hippies of the 1960s and the cavalier royalists of the 17th century wore their hair long, in contrast to their opposites, the ‘skinheads’ and the ‘roundheads’.
Human hair chiefly grows from the scalp, but may appear anywhere else on the body, especially the eyebrows, underarms and pubic region. Hair grows from beneath the skin. The living parts of hair lie beneath the skin, while the visible hair shaft (the cuticle) has no living processes. Damage to the hair shaft cannot be repaired by biological processes such as nutrition, though much can be done to help the cuticle remain intact.
Cosmetic hair issues can include unwanted body hair, thinning scalp hair, patchy baldness, pattern balding, loss of eyelashes and thinning of eyebrows.
Hair is made up of two structures – the follicle and the hair shaft. At the base of the follicle is a projection called a papilla and it contains capillaries, or tiny blood vessels, that feed the cells. The living part of the hair is the bottom part surrounding the papilla. It’s called the bulb. The bulb is the only part fed by the capillaries. The cells in the bulb divide every 23 to 72 hours, faster than any other cells in the body.
The follicle is surrounded by two sheaths – an inner and outer sheath. These sheaths protect and mold the growing hair shaft. The inner sheath follows the hair shaft down into the skin and ends underneath the opening of a sebaceous (oil) gland. The sebaceous gland is important because it produces sebum, which is a natural conditioner. After we reach puberty our bodies produce more sebum. Women’s sebum production decreases throughout their lives. The production also decreases in men, but not as much as in women.
The hair shaft is made up of dead, hard protein called keratin in three layers. The inner layer is called the medulla. The next layer is the cortex and it makes up the majority of the hair shaft. The outer layer is the cuticle. Most hair conditioning products attempt to affect the cuticle. There are pigment cells that are distributed throughout the cortex and medulla giving the hair its color.
Hair’s growth cycle
Hair on the scalp grows about 0.3—0.4 millimeters per day, or about 6 inches per year. Human hair growth and loss is haphazard and not seasonal or cyclic. At any given time, a random number of hairs will be in various stages of growth and shedding.
There are three stages of hair growth: catagen, telogen, and anagen.
Catagen – The catagen phase is a transitional stage and 3% of all hairs are in this phase at any time. This phase lasts for about 2—3 weeks. During this time growth stops and the outer root sheath shrinks and attaches to the root of the hair. This is the formation of what is known as a club hair.
Telogen – Telogen is the resting phase and accounts for 10—15% of all hairs. This phase lasts for about 100 days for hairs on the scalp and much longer for hairs on the eyebrow, eyelash, arm and leg. During this phase the hair follicle is completely at rest and the club hair is completely formed. If you pull out a hair that is in the telogen phase, you will notice at its root a tiny clump of hard, dry, whitish material. Normally we shed around 25—100 telogen hairs every day.
Anagen – Anagen is the active phase of hair growth, during which the cells in the root of the hair are dividing rapidly. When a new hair is formed it pushes the club hair up the follicle and eventually out through the skin. During this phase the hair grows about 1 cm (approximately ½ inch) every 28 days.
Scalp hair remains in this active phase for 2—6 years. It is hard for some people to grow their hair beyond a certain length because their anagen phase is short. Conversely, people who are able to grow their hair long have a prolonged anagen phase.
The reason why the hairs on the eyebrows, eyelashes, arms and legs are shorter than the hair on the head is because they have a very short active growth phase; around 30—45 days.
Curly or straight, shiny or dull?
The amount of natural curl a hair possesses is determined by its cross-sectional shape.
The more circular the shaft is, the straighter it is. The more elliptical the shaft is, the curlier or kinkier the hair.
The cross-sectional shape also determines the amount of shine the hair has. Straighter hair is shinier because sebum from the sebaceous gland can travel down the hair more easily.
The kinkier the hair, the more difficulty the sebum has traveling down the hair, therefore the more dry or dull the hair looks.