Some eye colors and hair colors are less common than others. Some combinations of hair and eye color are also much rarer than others. In this article, I’ll describe the rarest hair and eye color combination in the world, and I’ll explain why it is so rare.
What is the rarest hair and eye color combination in the world? The rarest hair and eye color combination is red hair and blue eyes. The reason why this combination is so rare is because red hair and blue eyes are both recessive genes. Based on the Punnett Square, they would be the rarest when in combination with dominant genes or genotypes.
The Punnett Square is a simple square diagram showing a test cross of maternal and paternal alleles. (Alleles are a certain form of gene).
The below Punnett Square example shows that if one parent has two dominant brown-eye alleles (represented by the capital letter brown “B”), and the other parent has two recessive blue-eye alleles (represented by the lower case blue “b”), then the child will have brown eyes.
In combination, recessive alleles are typically dominated by dominant alleles. There are rare times when recessive alleles are in combination with each other, just like the case of red hair and blue eyes. In this case, both of the traits appear, and the individual demonstrates such characteristics through physical appearance.
Other factors can also affect the production of red hair and blue eyes. Read on to learn more about the red hair and blue eye combination – the rarest hair and eye color combination in the world!
What Is the Rarest Hair and Eye Color Combination in the World?
The Punnett square I described earlier can best represent the scientific basis of gene combinations . It is a mathematical and scientific table of how alleles combine and form phenotypes. The primary rule is that dominant alleles rule over the recessive alleles when combined.
The square shows the possible resulting characteristics after the combination of the inherited genes coming from both parents. There can be different phenotypes that could come out from the combination of both parents’ genes.
Red Hair and Blue Eyes
Red hair with blue eyes is the rarest hair and eye combination in the world. The genetic variant that causes red hair comes from one type of melanin, which is the reddish pheomelanin. Redheads usually have an abundance of this pheomelanin and little eumelanin.
Sometimes, the pheomelanin is balanced by the action of the melanocortin 1 receptor (MC1R). It’s a protein found on the surface of melanocytes, which are cells responsible for the color of your skin, hair, and eyes. Typically, redheads have hazel, green, or brown eyes, and in rare instances, blue eyes.
As a side observation, it has been found out that red-haired people are more susceptible to thermal pain than people with other hair colors.
Why Is This Combo Rare and How Rare Is It?
Red hair with blue eyes is rare because this variant only has a low percentage in the human population. Since the traits are inherited, and there is a slim percentage of people with these genes, it follows that there are rare individuals with these characteristics (red hair and blue eyes).
There is only 1-2% of the world’s population with red hair– that’s around 70-140 million people.
On the other hand, the percentage of people with blue eyes is 17%, which is roughly 2.9 billion people of the 17.6 billion+ world population. These numbers are based on research conducted by the University of Melbourne .
Meanwhile, 0.17% has both red hair and blue eyes, which is only about 13 million people out of the world’s population. Definitely rare, isn’t it?
The chances of you getting this hair-eye combination would be rare unless you have ancestors who have had red hair and blue eyes. Remember that your inherited genes play a major role in your phenotype.
Where Does Red Hair with Blue Eyes Originate From?
Reportedly, Caucasian males have more chances of having blue eyes than females. However, red hair is more likely seen in women than in men. There’s still no extensive research on the frequency of both traits in men and women.
Approximately 10-30% of redheads are more common in Scotland and Ireland, while people with blue eyes usually come from Northern Europe, particularly in the Baltic regions.
Brown Hair and Green Eyes
There is only 2% of the world’s population with green eyes. However, there are many individuals with brown hair. In Asia, there would be rare people with green eyes and brown hair. Nevertheless, in Europe, Canada, New Zealand, and the US, people with brown hair and green eyes are not rare.
Brown Hair and Blue Eyes
This hair-eye color combo is not rare as there are about 80% of people who have brown hair, with 50% of them having blue eyes. This trait is common among white people. It’s not considered a rare hair and eye combo because 40% of these groups have these physical characteristics.
Most people with blue eyes and brown hair originated from the UK, US, Australia, and Canada. Many Asian people have brown hair, and some mixed races have blue eyes as well. So, brown hair with blue eyes is, more or less, common.
Celebrities with Red Hair and Blue Eyes
1. Nicole Kidman
2. Amy Adams
3. Christina Hendricks
How Does a Person Get Red Hair and Blue Eyes?
You can acquire these physical traits quickly through hair dyes and contacts. But if you want to learn the natural way of obtaining these physical features, then we have to inform you that it’s impossible to have these traits unless you have the gene variant that corresponds to red hair and blue eyes.
You inherit your genes from both of your parents, and if your parents or ancestors don’t have the ‘red hair and blue eyes’ gene variants, you can’t have these colors.
Both the red hair and blue eyes genes are recessive, so when they combine with brown hair and brown eyes, which are both dominant, the person has lesser chances of acquiring such colors. But somewhere down the line, an offspring would.
However, there are rare instances in which the parents can have both recessive genes that would allow the manifestation of red hair and blue eyes in their offspring. When one parent only has the recessive gene, there’s a 50% chance that the child can acquire such physical features.
You can predict the outcome by using the Punnett square. By plotting the gene variants of the parents, you could come up with the probabilities of inherited hair and eye colors.
Factors Affecting the Combination of Red Hair and Blue Eyes
Genes play a pivotal role in acquiring red hair and blue eyes. As previously stated, when parents have the genes associated with red hair and blue eyes, they would most likely produce an offspring of such traits.
Nevertheless, your inherited genes would also be dependent on the type of alleles that your parents have. So, both hair and eye colors are also dependent on other gene variations. Ultimately, the outcome would still depend on your parents’ genes because you inherit 50% from each of your parents. Your parents’ genes can also produce different phenotypes among your siblings.
Here’s an example:
Color of Hair
- Mother – Brown and Red genes (the dominant brown wins over the recessive red)
- Father – Red and Red genes (red is retained since no dominant gene is present)
When these genotypes are combined:
- Brown-haired Offspring – Brown (from mother) + Red (from father)
- Red-haired Offspring – Red (from mother) + Red (from father)
As you can see in the results, there can be a brown-haired and a red-haired offspring, but the dominant brown would appear more often than the recessive red. Out of four children, there may be three brown-haired children and one red-haired child.
Color of Eyes
- Mother – Brown and Blue genes (the dominant brown wins over the recessive blue)
- Father – Blue and Blue genes (blue is retained as no dominant gene is present)
When these genotypes are combined:
- Brown-eyed Offspring – Brown (from mother) + Blue (from father)
- Blue-eyed Offspring – Red (from mother) + Blue (from father)
Thus, your parents can have children with brown and red hair, and children with brown and blue eyes.
The environment can exert specific influences on the resulting color of your hair and eyes. Reportedly, stress and food may influence the development of melanin in your body as you age.
As a person grows, the level of melanin also increases and can deepen the color of the hair and eyes. This increase also depends on which type of melanin is developed more. If the red pheomelanin is more abundant than the eumelanin, then red hair would be more pronounced.
Constant stress has been found out to reduce the production of melanin. When melanin production is dysfunctional, it can result in lighter colors of the skin, eyes, and hair.
Additionally, there are certain foods that can change one’s eye color. Examples are:
- Organic Honey – According to some observations, this natural food, when continuously consumed, can lighten the color of your eyes.
- Green Leafy Vegetables – These veggies can help increase the production of melanin; thereby, producing darker eye colors.
- Dark Berries – These fruits have antioxidant effects and increase the production of melanin, making your eye or hair color darker.
3. Underlying Conditions
Some underlying conditions or diseases in a person can cause the production of rare hair or eye colors. An example is a congenital disorder called albinism, in which a person’s real hair and eye colors become lighter because of the low production of melanin.
Another example is heterochromia, in which each eye has a different color. The other one can be blue, and the other one brown or green. This coloration is unnatural and does not belong in the percentage of people with red hair and blue eyes.
4. Artificial Methods
Artificial methods, such as hair dyes and colored contact lenses, can change the real color of a person’s hair and eyes. This method of changing hair and eye colors is only temporary. Ultimately, the artificial color disappears with time, and the natural colors would eventually come out.
Recently, however, hair dyes that could permanently stay on your hair are discovered. Such hair colors are not counted in the percentage of people with red hair and blue eyes because they’re not natural hair colors.
What Is the Most Common Hair and Eye Color Combination?
The most common hair and eye combination is brown hair and brown eyes. The reason is that brown is a dominant gene that retains when combined with other recessive alleles.
When a brown-haired parent combines with a red-haired parent, brown hair will most likely dominate the offspring. However, there may be one offspring with red hair when both recessive alleles from the parents are combined.
Around 55-70% of the world’s population has brown eyes, and about 71-80% has brown hair – that makes people with brown hair and brown eyes around 65-75% of the world’s total population.
However, it would also depend on what region you belong to. The majority of Asians have black hair and black or brown eyes. Europeans have more of the blue and green eyes and brown or lighter colored hair.
Naturally, no matter what nationality you belong to, the primary factor that would determine the color of your hair and eyes would be your inherited genes. As long as you have inherited the genes that produce a particular hair or eye color, you would, most likely, be displaying the color variants you inherited as you grow older.
Conclusion – Rarest Hair and Eye Color Combination
So, to recap, what is the rarest hair and eye color combination? Based on the world’s population, the rarest hair and eye color combination is red hair and blue eyes. Only 2% of the world’s population of 7.6+ billion people has red hair, and 17% of it has blue eyes.
Out of these people, only 13 million (0.17%) has both red hair and blue eyes. This color combo is so rare and exists mostly in people who are from Scotland and Ireland. Meanwhile, people with blue eyes typically are from the Baltic regions of Northern Europe.
As for brown hair and green eyes, the percentage depends on the region. The majority of people have brown hair, and 2% of the human population has green eyes. Thus, there would be a higher percentage of this color combination than that of the red hair and blue eyes combination, especially in Europe. On the other hand, the most common combo when it comes to hair and eye color in the West is brown hair and blue eyes.