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.
So it's impossible to predict with certainty whether or not you'll have curly kids. Not to mention, there is still the tricky balancing act between dominant and recessive alleles. Since curly hair is a dominant gene, there is a good likelihood that one or two curly-haired parents will produce a curly-haired cutie.
Genes responsible for hair color come from both parents. Although the genes passed down from a child's parents determine hair color, variations can result in a child having a different hair color than both parents.
The nature of hair follicles directly impact the texture of your individual hair strands. If the follicles are symmetrical, hair grows to be straight, whereas if the follicles are asymmetrical, they produce oval and circularly shaped hair that tends to curl as it grows.
It could be that neither of your parents have curly hair, but an ancestor did. Then the curly hair gene could have been passed down through generations and your parents are carrier of that gene, which manifested its trait in you!
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.
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.
Human hair comes with all sorts of colors, textures and shapes. Notably, African hair is more coiled and dry; Asian hair is straighter and thicker; and Caucasian hair is somewhere in between with around 45% having straight hair, 40% having wavy hair, and 15% having curly hair.
Lots of traits are statistically rare: Left-handedness (just 10 percent of the population!), curly hair (11 percent!), and blond hair (4 percent!), to name a few. But of the more than seven billion people on the planet, only 2 percent can claim to have this one special trait.
Follicle Shape- The shape of your hair follicle largely determines your curl. Oval follicle shapes produce curly hair while round follicles produce straight hair.
Genetics of Inheritance
While moms pass down an X chromosome to their children—since women have two x chromosomes—dads pass down either an X or Y chromosome. The presence of a Y chromosome determines whether your baby's a boy or a girl.
Mom passes down all (or mostly) straight genes, and dad does the same with his curly genes—your son, therefore, has an even split. Both parents somewhere in the middle – This middle-ground will create the widest variation in your kid's hair type.
The scientists, from the Genetic Epidemiology Laboratory at the Queensland Institute of Medical Research (QIMR) in Brisbane identified the TCHH gene (trichohyalin) on chromosome one as the major gene controlling the curliness of hair.
So, while curly-haired parents tend to have curly-haired kids, there's no guarantee it will happen. Because many different genes are involved, even a curly-haired parent can have—and pass along—straight-hair gene variations.
Several studies have demonstrated that curls are seen as attractive. What is this? In a survey by L'Oreal Paris, more than half of women use curling irons to style their hair. Many other studies have proven that curly-haired folks are seen as more attractive than those who wear their hair in different styles.
Curly hair is thought to be better at keeping mammals warmer than just straight hair alone. In fact, straight hairs interwoven with curls creates the last line of defense against heat loss.
And while the results did vary, in the end we found that 58% of the fellas agreed that curlier is sexier.
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.
In most cases, ethnicity has been classified into three groups: African, Asian and Caucasian. It has been reported that Asian hair is generally straight and is the thickest, while its cross-section is the most round-shaped among these three.
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.
The people of South Europe and North Africa have more curly and wavy hair than North Europe. Scotland and Ireland are a notable exception.
Follicles that are more oval in shape cause curlier hair to grow. Very tightly coiled hair is due to the nearly flat, ribbon-like structure of their follicles. This hair texture is very common in people of African ancestry. Not only is African hair often coiled, it also has a unique texture.
Water molecules are just like tiny magnets! The proteins in your hair are the same way. So when you walk into a humid room, it's like you're surrounding your hair with tiny magnets pulling your hair in different directions. This can make your hair curly or wavy that day.