The African hair is generally curly or frizzy, and grows almost parallel to the scalp. It has the slowest growth rate of 0.9 centimeters per month due to its spiral structure which causes it to twist on itself as it grows.
Growing afro hair can sometimes seem like an impossible task. One thing is for certain, however, and that's that it requires dedication and a whole heap of patience. Scientifically, black hair is the slowest growing hair type due to its elliptical shape and only grows about one third of an inch per month.
African hair has the lowest growth rate. Hair growth rate and hair diameter were reported to be associated with cuticle interscale distance. Hairs with larger cross-sectional area grow faster and have a shorter cuticle interscale distance, and vice versa.
The brittleness of African hair adds to the illusion that it cannot be grown long. The tight curls create stresses at each turn in the hair fiber. The hair strands become fragile, making them prone to breakage. As a result, tightly coiled hair tends to stay quite short.
In people of African descent, hair tends to grow around 0.2 inch (5 mm) per month, whereas Asian people's hair often grows much faster, at up to 0.8 inch (20 mm) per month, Sally-Ann Tarver, a trichologist at Cotswold Trichology clinic in England, told Live Science by email.
Black hair, because it's curly, can be weaker than straighter hair. Each bend in the strand represents a weak point in the hair shaft, which makes it more prone to breakage. All this means is that it takes a little more TLC to avoid breakage. So we tend to have shorter hair, but that doesn't mean it doesn't grow.
Asian hair grows the fastest among ethnic groups. It is also significantly less dense because fewer hairs are grown per square centimeter. However, Asian hair often appears dense because the follicles are generally thicker.
The average diameter, or thickness, of Asian hair is from 80 to 120 µm, compared to 65 µm in Caucasian hair and 55 µm in Black hair. The average diameter of Hispanic/Latino hair tends to fall between that of Asian and Caucasian. Caucasians have the highest hair density among the ethnicities studied.
Hair follicles can also affect the thickness of hair strands. African hair is seen to be much thicker and more dense meaning that the hair follicles are larger. Density represents the amount of hairs that grow from the head, with denser hair resulting from more hairs growing closer together from the scalp.
Frizz occurs on afro hair and curly hair more than any other types. Afro hair produces plenty of protective oils called sebum, but the oil struggles to spread evenly along the hair fibre due to the curly nature of afro hair.
There are racial differences, however, in the incidence of male pattern baldness. The highest rates are found among Caucasians, followed by Afro-Caribbeans. Chinese and Japanese men have the lowest rates. For some unknown reason, this form of hair loss is does not occur among Native Americans.
Black hair, because it's curly, can be weaker than straighter hair. Each bend in the strand represents a weak point in the hair shaft, which makes it more prone to breakage. All this means is that it takes a little more TLC to avoid breakage. So we tend to have shorter hair, but that doesn't mean it doesn't grow.
The Longest Hair in the World: The Women of the Red Yao Tribe In China.
And therein lies the problem. Science has revealed, that black hair tends to be more dry and brittle, and that can cause it to fall out and/or break off. But fortunately, there is a solution, and it's based on a scientific fact, so many overlook…iron. Yes, iron!
Fros don't absorb as much moisture as our caucasian cousins' hair, added to this the structure of our hair (curls and kinks, and increased density) means that nutrients often don't travel along the length of our strands as well as we'd like.
Sure, trimming your hair a few inches will definitely make your hair look and feel healthier, bouncier and lighter, but unfortunately, it won't aid in actual afro hair growth. All that happens when you trim your hair is the split ends, damaged and old hair are removed.
Higher Concentration of Melanin
Most Africans have high levels of melanin that results in yellow eyes. Melanin determines the color of your skin, sclera and eyes. When this concentration increases, the eye color becomes light yellow or muddy brown.
Even though natural black hair is dry, the build-up of debris can make it feel greasy if not washed regularly. You should ideally wash your natural black hair once every seven to fourteen days. Use mild cleansing hair products such as gentle shampoo and conditioner.
Caucasian hair
It grows obliquely, and grows about 1.2 centimeters per month. Caucasian hair has an oval shape. The density of Caucasian hair is the highest of the three ethnic groups, so it is the most dense.
Hair density.
Asians have approximately 150 hairs for every square centimeter on the scalp with about 80,000 hair follicles on an adult scalp. African Americans have the lowest hair density, averaging around 130 hairs per square centimeter and about 60,000 hair follicles on an adult scalp.
According to a global study based on 4 characteristics that determine healthy hair – thickness, tensile strength, shine, and smoothness – Indian women have the best hair in the world.
Your Genes
If your parents developed gray hair at a young age, chances are you will, too — and there's not much you can do about it. Race also plays a role in how early your hair turns gray. For instance, gray hair tends to occur earlier in Caucasians but later in Asians.
Many scientists believe that the reason why black people have kinky, curly hair is that it evolved that way to protect the hair from UV radiation from the sun. It is believed that Afro hair was genetically adapted to protect the scalp of the earliest modern humans in Africa.
African American hair has a high porosity, which means it can absorb moisture easily but also lose it quickly. On the other hand, Caucasian hair has a low porosity, which means it is more resistant to moisture but can be harder to penetrate with conditioning treatments.
Caucasian hair grows at a rate of about 1.2cm a month and has the greatest density of all three hair types.