Curly hair is considered a “dominant” gene trait. Straight hair is considered “recessive.” To put that in simple terms, that means that if one parent gives you a curly-haired gene and the other parent gives you a straight-haired gene, you'll be born with curly hair.
The gene for curly hair in Caucasians
It has been long established that curly hair is a dominant trait in Caucasians and straight hair is recessive.
If both of your parents were born with curly hair, chances are that you'll be born with curly hair, too. But there are cases where two curly haired parents can produce a child with straight or wavy hair. Curly hair is considered a “dominant” gene trait.
Hair morphology is one of the more conspicuous features of human variation and is particularly diverse among people of European ancestry, for which around 45% of individuals have straight hair, 40% have wavy hair, and 15% have curly hair.
Curly hair is dominant, so someone is more likely to have curly or wavy hair if at least one of their parents does. Recent research points to trichohyalin, a protein in hair follicles, as having primary influence over hair curl. However, there are many genes contributing to hair curliness, most of them unknown.
Curly hair is determined by factors you inherit from your biological mother and your biological father. There's no single gene that determines the way that your hair looks. The way your hair looks when you're born is also a clue into the genetic information you'd pass to your own children if you have them.
Hair morphology is one of the more conspicuous features of human variation and is particularly diverse among people of European ancestry, for which around 45% of individuals have straight hair, 40% have wavy hair, and 15% have curly hair.
Hair type 1A is super-straight. It doesn't even hold a curl! 1A is the rarest hair type. It is usually found on people of Asian descent.
Asian hair is also the straightest hair of any ethnic group. According to HealthGuidance, African American hair texture varies. Some people have thicker, coarser hair whereas others have finer hair.
Type 1: Straight Hair
Type 1A hair is very straight and fine, with no hint of wave or curl. As it is so straight and fine, when the natural oils travel to the ends, it tends to cause it to look like oily hair. It is the rarest hair type and is common among women of Asian descent.
Curly hair is not certain to a race or ethnicity, it appears all over the world in many forms. White, brown, black and everything inbetween! There is also a scale on which curly hair is classified (2a-4c).
In fact, more people prefer curly hair to straight hair. Though beauty is seen differently by everyone, one thing is for sure; curly hair is getting a lot of love lately. In fact, in a survey conducted by StyleCaster, a surprising 58% of guys thought curly hair was sexier than other hair textures.
The Hair-Do Hormones:
At times of great hormonal shifts, like puberty, pregnancy and menopause, many strange things can happen to the human body. Skin texture can change, the ability to put on or lose weight might not be the same and, sometimes, hormonal changes can literally curl (or straighten) your hair!
One popular myth is that hair loss in men is passed down from the mother's side of the family while hair loss in women is passed down from the father's side; however, the truth is that the genes for hair loss and hair loss itself are actually passed down from both sides of the family.
The probability of the parents having a child with curly hair is 3/4, as shown in the Punnett square below: A Punnett square for the cross of two heterozygous parents is shown.
Many Asians have naturally straight hair, but there is a significant group of us who do have naturally curly or wavy hair! However, because it's the norm to see straight and sleek hair, curly haired boys and girls tend to think that their hair is some kind of unruly straight hair that isn't behaving.
Caucasians have the highest hair density among the ethnicities studied. Black people have the lowest. Asian people have hair density that falls somewhere in between.
Certain races have higher rates of hair loss compared to others. Caucasians have the highest rates out of all the ethnic groups. On the opposite end of the spectrum, Native American Indians, Inuits, and Chinese have the lowest rates.
Caucasian, Asian and Indian hair samples were put to the test for the World's Best Hair study. Their results put an end to any splitting of hairs over the issue: in terms of health, the Indian hair is the best, topping other ethnic groups on all four counts.
In terms of both male and female preferences, blonde was considered the next best choice after brunette hair. According to the study, 27 percent of males chose the blonde photo of the woman to be the most attractive, while 23 precent of women similarly preferred the blonde hair.
Fine hair texture is the most delicate and fragile hair type. Typically, type 2 waves and type 3 curls fall into this category. However, you can find fine hair across a wide variety of curl types. If you find that your hair is both fine and curly, it can be quite the challenge to perfect your curls.
Yes, only 11% of the population have curly hair.
Less than 20% of people have naturally curly hair. The percentage gets even smaller when you consider the scores of guys out there who don't embrace their curls.
With Caucasians, research shows that “45 percent of European people have straight hair, 40 per cent have wavy hair and 15 per cent have curly hair.” Curly hair is not exclusive to one race and it does not mean you have to be mixed raced to have curly hair. It's actually not rare for Caucasians to have curly hair.