​Will My Baby Have Red Hair? A Genetic Explanation

Wondering if your baby could be a redhead? Red hair, sometimes called ginger hair, is the rarest natural hair color in the world, so what are the odds your baby will be born with red hair?

It all depends on what color hair Mom and Dad have. 

Related: What Color Hair Will My Baby Have? (A Genetics Guide)

Just How Rare Is Red Hair?

About 1-2% of the world’s population have red hair, although it is more prevalent in the northern hemisphere where this percentage rises to 2-6%. The countries that have the highest percentage of redheads are European, with Celtic countries topping the list. 

Ireland has the highest percentage of redheads with approximately 10% of the population having red hair. Scotland comes in second with roughly 6% of the population having red hair (although some sources estimate it to be as high as 13%).

However, the country with the highest number of redheads is in fact the United States due to its large population. 

As of 2018, the US was home to around 18 million redheads - more than all those found in Ireland and Scotland combined. It is notable, however, that the majority of US redheads are believed to have Northern European ancestry.

What Determines Hair Color?

Natural hair color is determined by how much of a colored pigment called melanin is in your hair, and what kind it is. There are two types of melanin – eumelanin, a dark pigment, and pheomelanin, a lighter one. 

People who produce lots of eumelanin tend to have darker hair, while people who have more pheomelanin are usually blond or redheads. This lack of pheomelanin also causes fair skin that won’t tan and freckles. 

This goes some way to explain why redheads are more common the further north of the equator you go. Eumelanin blocks UV light and protects you from the damaging effects of UV rays – a useful thing to have if you live in a country that gets plenty of sunlight all year round!  

However, Eumelanin can also be harmful in countries where there is a lack of natural sunlight in the winter months like Ireland and Scotland. Having less eumelanin will help your skin absorb some UV light in order to make the vitamin D it needs.  

How Is Red Hair Inherited?

There is no “ginger gene” but a gene on chromosome number 16 called melanocortin 1 receptor (MC1R) is involved in skin and hair color. The MC1R gene codes for a protein – the melanocortin 1 receptor – which sits on the surface of cells that produce pigments (melanocytes). 

When the receptor is stimulated by a signal, it causes the melanocyte to produce the dark pigment eumelanin. If the receptor is not activated or blocked, it produces the lighter pheomelanin.

People with red hair have a variation of the MC1R gene (a common gene mutation called a polymorphism). Their receptor is less able to respond to the signal, so it makes little or no eumelanin. 

Red Hair Comes in Different Shades of Red and Orange 

Things get a little more complicated when you consider that we all have two copies of each gene - one from each parent. If baby inherits two copies of the MC1R variant they are likely to have tresses that are “classic red”, and appear quite orange, as they will produce mostly pheomelanin and little eumelanin. This explains why two red-headed parents are very likely to have red-headed children.

However, if baby inherits the combo of one copy of the variant allele and one functioning allele then eumelanin production is lower, while pheomelanin production is higher. This could result in different shades of red like strawberry blond, chestnut, or auburn hair.

Most people have two functioning copies of the MC1R gene, one inherited from each parent. These individuals have black or brown hair, because of the high amount of eumelanin. 

If Both Parents Have Red Hair Will Their Child Always Be a Redhead? 

You may think that if mom and dad are both rocking red locks, they must have a red-haired baby. However, Nothing in the world of science is ever this simple!

A study published in 2018 used genetic data from 350 000 UK volunteers and found that some people who had two copies of the MC1R variant didn’t have red hair, but instead had brown or blond hair (Morgan et al, 2018). They concluded that this is because there are a few genes other than MC1R that affect the trait. 

Another finding surprised even the scientists, they discovered that genes that control hair texture and shape also play a role in determining hair color. They rationalized this by concluding that the speed at which hair grows affects how much pigment the hair picks up, with slow hair growth causing dark hair. The thickness of the hair strands can affect the way pigment looks.

Does Having Red Hair Affect You In Other Ways?

Having two copies of the “red hair gene,” – the MC1R variant – not only gives you red hair but may also affect your sensitivity to pain. One study found that people with red hair perceive pain differently than others  and may have a lower pain tolerance (Liem EB et al, 2005). 

Do Red Heads Need More Anesthesia? 

Due to this lower pain tolerance, studies have also found that surgeons need to use more anesthetic on redheaded women compared to brown haired women to sedate them (Liem EB et al, 2004). According to researchers at UCI Health, patients with red hair may need about 20 percent more anesthesia to be sedated during a dental appointment or surgical procedure! 

The theory behind this is that the MCR1 protein has a dual function - the one involved in pigment production as previously discussed and also as a receptor for endorphins – hormones that block pain signals.

Can A Baby Have Red Hair If Neither Parent Does?

The simple answer to this is yes! Red hair is seen as a recessive trait and darker hair is seen as a dominant trait. If a child inherits the gene from both parents they will probably (although not certainly) have red hair. 

Ever heard of someone saying that they get their red hair from a distant relative? 

This is because red hair can skip generations, appearing at intervals throughout the family tree when two recessive genes are inherited. This means even if you have brown or black hair you may still carry the MC1R variant gene and pass this on to your children

Can Red Hair Change Color Over Time?

Most of us are born with lighter hair that can darken as we age so if baby’s hair is strawberry blond or light red hair they may end up with darker hair that can be red or auburn. They may even lose their red locks, but most likely their hair will have some red undertones to it that may only be visible in the sun or come out in other ways like in a man’s beard.

We all lose the pigment in our hair as we age but redheads tend to keep hold of the color for longer, fading through a spectrum of faded copper to blond and then silvery-white.

Family Background May Be the Biggest Clue

If you have Irish or Scottish ancestry, the chances of your baby being born with red hair are more likely. This is especially true if both parents share this heritage. 

If not, it is very unlikely that your child will have fiery red locks or even red tones. But remember that red hair originated as a mutation. Nothing is impossible!