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.
In order to be a redhead, a baby needs two copies of the red hair gene (a mutation of the MC1R gene) because it is recessive. This means if neither parent is ginger, they both need to carry the gene and pass it on — and even then they will have just a 25% chance of the child turning out to be a redhead.
Since red hair is a recessive trait, the children of two redheaded parents will almost always be redheaded as well. In contrast, if only one parent is redheaded and the other has brown hair, there is a higher chance that the children will display the dominant trait and will have brown hair.
Because it's a recessive trait, red hair can easily skip a generation. It can then reappear after skipping one or more generations if both parents, no matter their hair color, carry the red hair gene.
Lifespan: up to 20 years in captivity, 5-10 years in the wild.
Other Sacharov redlines: "The connection between red hair and a fiery temperament may be more than just an old wives' tale. An Israeli psychiatrist reported that redheaded children are three to four times more likely than others to develop hyperactivity.
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.
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.
One of the many facts about redheads is that their hair will never turn grey. The pigment in their hair that causes it to be red will just fade over time, causing their hair to turn blonde or white, but never grey.
One popular myth is that hair loss in men is passed down from the mother's side of the family while hair loss in women is passed down from the father's side; however, the truth is that the genes for hair loss and hair loss itself are actually passed down from both sides of the family.
Contrary to what many people assume, redheads did not originate in Scandinavia, Scotland or Ireland, but in central Asia. Their coloring is due to a mutation in the MC1R gene that fails to produce sun-protective, skin-darkening eumelanin and instead causes pale skin, freckles and red hair.
Ginger is a recessive trait. With no dominant trait present in either parents, they can only pass on the recessive ginger trait to their offspring.
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.
But redheads age better because the MC1R gene helps them look two years younger on average than they actually are. They also produce more Vitamin D protecting against rickets which weakens bones and tuberculosis which can be fatal.
Irish immigrants arriving in Australia looking for labour gained a reputation as heavy drinkers and fighters, with 'blue' being local slang for a fight. The term evolved to come to mean a redheaded Irishman.
Ireland has the highest per capita percentage of redheads in the world -- anywhere from 10 to 30 percent, according to Eupedia, a website that explores European genetics and ancestry. They are almost equally prevalent in Scotland and other pockets of Celtic pride.
Research has shown that people with red hair perceive pain differently than others. They may be more sensitive to certain types of pain and can require higher doses of some pain-killing medications. However, studies suggest that their general pain tolerance may be higher.
Fun facts about red hair strands
Redheads are less likely to go grey. The pigment in red hair typically fades over time from red to blonde and white, but not grey. Redheads produce more Vitamin D in a shorter amount of time than people with other hair colors.
Strawberry blonde is lighter than red hair. 'It's extremely rare for people to have hair that is naturally a strawberry blonde color.
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.
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.
They easily detect changes in hot and cold temperatures. They may be less sensitive to electric shock, needle pricks and stinging pain on the skin.