The Genetics of Hair Color

Why Wasn’t I Born Blond?

They say that blondes have more fun, which is just one of the reasons why so many of us get our hair color from a bottle. Only two percent of all the people in the world are naturally blonde, yet it is the hair color that is most often associated with sexiness, health and prosperity.

If you’re wondering why you weren’t blessed with masses of thick, golden hair, the answer lies in genetics.

Melanin Gives Hair its Color. The color of your hair is determined by how much melanin is present, and there are two types in human hair: eumelanin and pheomelanin. High levels of eumelanin lead to darker hair shades, while high levels of pheomelanin lead to redder in the hair. Naturally blonde hair results when hair is deficient in both types of melanin.

You may have seen pictures of yourself as a child with blonde hair, which might be heartbreaking if the golden locks you dream of are now gone. Eumelanin levels in hair usually increase with age due to blonde genes being “switched off.” This explains why so many blonde kids gradually go darker as they grow up.

The Genetics of Hair Color

So, now you know why you’re not one of the lucky two percent, but you’re probably thinking: Why is there more eumelanin in my follicles than in my friend’s? If you’re envious of a friend’s golden curls, you should direct your anger toward genetics.

While there’s still some disagreement among scientists about the exact role genetics plays in hair color, there’s general agreement on a theory that at least two pairs of genes are responsible.

The amount of eumelanin in your hair is directly linked to the genes from both your parents. Each of your genes is made up of DNA sequences called alleles. Each of your physical traits is determined by a gene, which consists of two alleles — one from your mother and one from your father. The two alleles can be the same, or they can be different.

The gene that possesses the dominant brown allele and the recessive blonde allele is the most common among humans, and results in brown hair. A person with no brown alleles will have blonde hair. The exact shade of brown is determined by several genes working together.

Your parents each possess several hair color alleles; which of them you received in the womb was a completely random process. This explains why three siblings can each have a different hair color. So, the next time you get angry at having to spend a small fortune on dying your hair blonde, blame your parents.

Hereditary Hair Loss: It’s in the Genes.

You can also blame your parents for genetic hair loss. If you’re suffering from male pattern baldness or female hair loss, no matter what hair color or style you want, and you are considering doing something about it, we encourage you to contact us to schedule a free, no-obligation hair and scalp evaluation and to explore the various hair restoration options that are available today.