Red Sonja | Millennium Films

The stereotypes aren’t entirely unfounded.

My son Henry was born by C-section, his massive skull too much for traditional methods to push through. As the doctor lifted him out of my wife’s open midsection, my eyes were drawn like a magnet to the vibrant, absurd shock of red hair that circled his head.

My wife is blonde. I’m a brunette. So Henry’s fiery coif came as a surprise to both of us. We thought it would fade over time, but ten years later, it’s still as flame-bright as ever.

Red hair has an unusual attraction. Only two percent of the population has it, typically caused by a mutation in a gene called M1CR that causes hair follicles to express a protein called pheomelanin. The mutation is recessive in about 40% of the population, but when two carriers of the recessive gene make a baby, that baby can express the mutation — that’s what happened with Henry. When we look back into our family trees, we can see red hair popping up here and there, in half-siblings and grandparents, but there’s no rhyme or reason to it.

Two percent is a pretty scant number by comparison to the oceans of blondes and brunettes out there. No matter what your heritage or ethnic group, redheads are still going to be a minority. That status has led to a number of stereotypes about gingers that have persisted for thousands of years.

Red-headed women are viewed as loose, libidinal and wild. Red-headed men are temperamental and quick to violence. Never mind that there’s no actual evidence behind these perceptions — they’ve become ingrained in our minds all the same.

So what lies at the root of these ideas about red hair? A fascinating mix of genetics and culture.

In northern Europe, it’s speculated that the M1CR mutation was brought to the mainland from the Viking raiders of Norway. The greatest concentration of red hair is found in Scotland and Ireland, and the coastal areas where the Vikings settled show the highest number of gingers.

One of the oldest Norse documents, the Prose Edda, has an interesting little bit of redhead history. In it, Odin the All-Father, ruler of the gods of Asgard, is described as being a wise and thoughtful ruler with blonde hair. His son Thor, though, is possessed of a full head of red hair, an enormous bushy red beard, and a temper quick to flare.

The Vikings weren’t polite sorts, and it’s not terribly surprising that their reputation for violence got married to their hair color. But northern Europe wasn’t the only place on the globe where redheads were getting a bad rap.

The thing is, the M1CR mutation didn’t start in Norway. Jacky Colliss Harvey’s “Red: A History Of The Redhead” tracks it back to the steppes of central Asia, 3,000 or 4,000 years ago. Those early redheads had a genetic advantage when they moved north, as their pale skin synthesized more vitamin D from the weak sunlight.

Red hair was also the mark of the Thracians and the Scythians, two loosely-organized tribal groups that harried the borders of ancient Greece. Considered uncivilized, they actually had advanced art and literature, but without political consolidation they never built an empire and were eventually subsumed and enslaved by the Persians. In Greek art from that time, they’re depicted with vivid red hair, engaged in fierce and brutal battle.

When Rome tried to expand their empire to the North, they came into conflict with the ruddy Celts, descendants of those Viking raiders, who presented some of the most vicious resistance they’d yet seen. That furthered the connection between martial strength and flame-colored hair.

In Biblical times, Judas the betrayer of Christ was often portrayed as a redhead. That was intentional, as a way to “other” him from Jesus’s remaining dark-haired apostles while also sneaking in subtly anti-Semitic stereotypes. That portrayal — perhaps more than any other — has influenced the perception of redheads as villains around the world.

An interesting side effect of this stereotype is that history is often rewritten to give red hair to people that might not have had it. One of the most famous examples is the legendary warlord Genghis Khan, who in a history written by the Persian Rashid al-Din is described as “long-bearded, red-haired, and green-eyed.” This seems unlikely, considering the dark-skinned traditionally Asiatic features present in contemporary descriptions of the Mongols, but the M1CR mutation was found in the area. It’s possible that al-Din embellished his description after the fact to add physical features that his culture associated with violence.

We’ve been talking about stereotypes, but there are actually some genetic side effects from the mutation that causes red hair that could be responsible for that violent reputation. A 2004 study showed that redheads require more anesthetic to dull pain and are resistant to topical numbing methods like novocaine. They also feel cold temperatures more vividly. That increased pain sensitivity could result in bad temper for sure.

And it’s not just hair. We probably should have mentioned that in nearly every society, the color red is associated with danger. Stop signs, fire, blood — when you see red, stay away. Scientists are discovering that reaction might be hard-wired into the brains of primates.

A 2011 study on rhesus monkeys had workers place food in front of the animals while wearing shirts and hats in red, green and blue. The monkeys unfailingly picked up and ate the food from the green and blue people, but stayed away from the red ones, choosing to leave the snacks uneaten. Obviously the color acts as a trigger in their brains as well.

It’s not just our closest relatives in the animal kingdom, either. Although there hasn’t been a scientific study on it, common wisdom is that redheads get stung by bees more often than any other hair color. Whether that’s a result of their coif, a pheromonal change, or something else is hard to say.

When you’re born with a color that the world reads as dangerous on top of your head, it can be tough. Prejudice against redheads is still a going concern in modern society. In England, students at many schools declared November 20th to be “Kick A Ginger Day,” inspired by a “South Park” episode. They’d better be careful, though. If the world’s redheads rediscover their wild Viking heritage, they could do a lot of damage.

I’m not too worried about my son, to be honest. His red hair makes him stand out in the crowd, a wild flame that can’t be quenched by the rain. It’s the symbol of his proud Viking heritage, showing up unexpectedly to tell the world that he’s part of the 2%.