Less than 2 percent of the world's population has red hair, making it the rarest hair color in the world. It's the result of the mutated MC1R gene. If both parents carry that gene, their child has a 25% chance of getting lovely, red locks, even if the parents don't have red hair themselves.
People with red hair are likely more sensitive to pain. This is because the gene mutation (MC1R) that causes red hair is on the same gene linked to pain receptors. It also means redheads usually need more anesthesia for dental and medical procedures. Having red hair isn't the only thing that makes some redheads unique.
About 1–2% of people of European origin have red hair. Especially female redheads are known to suffer higher pain sensitivity and higher incidence of some disorders, including skin cancer, Parkinson's disease and endometriosis.
Lifespan: up to 20 years in captivity, 5-10 years in the wild.
The DNA for blonde or red hair is not as strong as brown. In order to have blonde hair, both of your alleles need to be blonde. The same is true for red hair. These are recessive traits.
According to an article by evolutionary biology professor Mark Elgar, PhD, of the University of Melbourne, blue-eyed redheads are the absolute rarest, with 0.17% of the population having that combination of hair and eye color.
One study shows that, contrary to popular belief, redheads are not weaker than blondes or brunettes. After studying the effect of pain in humans, researchers found that redheads appear to be "better protected" on the surface level.
Less than 2% of the world's population have red hair
Scotland boasts the highest percentage of natural redheads, with 13% (40% might carry the gene there) while Ireland comes in second with 10%.
Ireland has the highest number of red-haired people per capita in the world, with the percentage of those with red hair at around 10%. Great Britain also has a high percentage of people with red hair.
Back in the 1500s, it was said that witches in France would blaspheme the name of the Virgin Mary by calling her 'la Rousse', the redhead. Red hair was said to be a sign of witchcraft in Christian Europe, and was often enough for a witch finder to pronounce guilt on someone.
Previous studies had shown that redheads inherit two versions of the MC1R gene that leads to red hair – one from their mum and one from their dad. Although almost everyone with red hair has two copies of the red-haired version of MC1R, not everyone carrying two red-haired versions is a redhead.
Redheads have much more pheomelanin than eumelanin in their bodies. That's why their skin tone is often so light, and why their hair is often reddish.
Red hair is caused by a mutation in the MC1R gene. It's also a recessive trait, so it takes both parents passing on a mutated version of the MC1R gene to produce a redheaded child. Because it's a recessive trait, red hair can easily skip a generation.
And, while redheads are often stereotyped as stubborn, this isn't necessarily a bad thing. As a matter of fact, that resoluteness is linked to a particular quality of your tresses; red hair doesn't go grey easily, and the strands of hair hang onto the colour for a long time, even if it becomes slightly faded.
A study headed by Dr. Edwin Liem at the University of Louisville in Kentucky found that redheads are more sensitive to hot and cold, and are hurt by the cold at temperatures nearly 11 degrees Fahrenheit warmer than others.
Having red hair and blue eyes is the rarest hair/eye color combination possible. The odds of a person having both of those recessive traits is around 0.17%. Instead, most redheads have brown, hazel or green eyes, according to Medical Daily.
Some evidence suggests redheaded adults often appear older than their actual age. For example, one study published in 2016 in Current Biology found that adults who carry two copies of the MC1R gene variant are more likely to look two years older than other people their age.
Humans and mice with red hair have a different tolerance for pain because their skin's pigment-producing cells lack the function of a certain receptor. Lack of this receptor function causes changes that tip the balance between pain sensitivity and pain tolerance.
It is a commonly held clinical belief that people with red hair respond to medications differently from those with other hair colors. "Redheads are a 'tough knockout'" is a commonly heard aphorism among anesthesiologists. Now, there is valid evidence that the saying is true.
Having natural red hair is rare (like, two percent of the population rare), so coming across someone with natural strawberry blonde hair isn't common.