Gingers

I recently had a conversation with a crazy red-headed friend of mine about his crazy red-headed ex-wife and why their crazy red-headed daughter is so crazy. You know the stereotype: redheads are supposed to be sharp-tongued, hot-headed, sex-crazed nutjobs. This led me to wonder: Are redheads actually nutjobs, and if so, why would that be true?

My first instinct is to say that the stereotype is bunk. It fits a pattern of maligning every genetic phenotype for the purpose of convenient pigeonholing, and holds no more water than saying that all blondes are dumb, or that big-handed men are well-endowed. The world population of redheads, currently estimated at 1%, would seem to have no more nutjobs in it than any other hair color, and there are plenty of level-headed gingers in the world. The recessive gene that gave us Caligula was the same that gave us Queen Elizabeth I.

Though as far as “sex-crazed,” we can only fantasize.

(In the interest of full disclosure: While not a redhead per se — my hair color was once described by a hairdresser friend as “medium maize” — I come from a redheaded family and even express the gene in the form of a perfectly ginger beard when I go too long between shaves. So as a below-the-ears redhead, I’m not exactly neutral. However, I can say objectively that my immediate family is composed of sharp-tongued hot-heads of which I am one. As for the sexual proclivities of redheads, I’ll decline to comment because, hey, that’s my sister.)

Cultural stereotypes aside, I’m intrigued by the fact that a gene for coloration could carry with it a gene for some other effect. For example, the efficiency of some birds’ immune systems are linked to plumage color. And as Darwin noticed, albino animals are more prone to deafness. So is it possible for the redhead gene to carry with it another gene which might influence behavior? Actually, yes.

First: A Natural History of Redheads. Red hair is caused by the pigment phaeomelanin, which is in turn caused by a mutation in the melanocortin 1 receptor (MC1R) protein which is controls what type of melanin our cells produce. So, essentially, redheads are mutants. But the reason for the evolution of this mutation is unclear. It is found in people worldwide, even in Africans, Aborigines and Persians, but of course it’s most prevalent in Western and Northern Europeans, where it is expressed by 2-6% of the population. One theory posits that the defective MC1R receptor was successful in Europe for the same reason white skin was: pale people absorb more heat and more ultraviolet radiation, which can make all the difference in sun-forsaken countries prone to Vitamin D deficiencies. Essentially, the MC1R mutation served to make your whites whiter. (The Neanderthals possessed the ginger gene, too. Somewhere in prehistoric Europe was a club-wielding caveman Ron Howard.) The only problem with this theory is that there’s no evidence for positive selection in this environment; blondes get sunburns just like redheads, so the recessive gene shouldn’t have given any advantage to our freckly forefathers and should thus have been squelched.

Also, it can’t explain why Carrot Top’s ancestors weren’t violently erased from the genetic line.

A second proposal is that red hair was promoted not by competitive selection, but by sexual selection. (Somewhere in prehistoric Europe was a berry-picking, wolfskin-clad Christina Hendricks.) As a fan of redheaded girls as much as the next guy with a pulse, I’m more inclined to trust this hypothesis. After all, phaenomelanin is also the pigment responsible for the red coloration of the lips, the nipples, the head of the penis, and the vagina. The secret to your good looks, my redheaded readers, is your vagina-colored hair.

Sexual selection for the mutated MC1R receptor among early hominids.

But what the mutant MC1R receptor also carries is a different relationship to pain. The same MC1R receptor that receives the melanocyte-stimulating hormone which colors your hair also receives another, more popular hormone: endorphins. (The two hormones are structurally similar.) A 2005 study concluded that redheads are more sensitive to thermal pain, while another found that redheads feel more pain at the dentist and needed 20% more anesthesia than blondes or brunettes. However, another study was said to prove that redheaded women have a higher pain threshold than blondes and brunettes, at least when the pain was noxious (such as electric shocks) and not thermal (such as a curling iron). So, which is it? Are redheads pansies or bad-asses? Are they both? Are they neither? And if red hair really does effect pain thresholds, would that say anything about a common behavior?

As if this article couldn’t get ridiculous enough, let’s make an awkward segue into the “zoological mystery” segment of our program: What if the answer to redheaded temperament and licentiousness could be found in those ultimate redheads, the orangutans?

Follow my twisted logic here. The MC1R gene is responsible for pigmentation in all mammals, and a mutation in it serves to make pigs pink and red pandas red. There’s even reason to believe there were a few ginger-colored woolly mammoths in the world. So do orangutans, a great ape like us, possess a greater tolerance for pain, or a weaker one, and are they hot-headed sex-crazed nutjobs?

A Natural History of Orangutans: They are the only great ape native to Asia, found only on the islands of Indonesia and Malaysia. They are also the least social ape, traveling through the forest solo or in small mother-child units, but this has less to do with antisocial behavior than with the relative scarcity of fruit in their homelands. Unlike the omnivorous chimps or salad-munching gorillas, bulky frugivorous mammals such as orangutans have to space themselves out or risk starvation. But when the forest produces a glut of fruits, orangutans are happy to share it with each other, and congregate in some numbers for mostly-peaceful reunions. These social events help the otherwise solitary orangutans retain a culture. Like other apes, they possess language. But what sets orangutans apart from chimpanzees or gorillas is their capacity for tool use. Orangutans are arguably the best tool-makers in the world besides us: they teach each other to use sticks to extract insects or seeds, how to use certain plants as medicinal balms, or how to curl leaves into cups to drink water or roll them into primitive megaphones for better communication. They even use leaves as toilet paper, and have the capability to make tools for making other tools, a quantum leap forward in intelligence.

Yeah yeah yeah, but are they nutjobs? Survey says no. At least, not more so than any other territorial animal. They have skirmishes at the borders. Immature males try to forcibly breed with females and are either rebuffed by the females or by local dominant males. Nothing out of the ordinary for apes. And as for pain tolerance, we fortunately have not hooked orangutans up to electrodes or curling irons to test it. The MC1R gene in orangutans, it turns out, is mutated differently than in humans: we produce red hair via different pathways. So, why is the orangutan orange? Is it to absorb sunlight in the dark forests of Borneo? Or is it sexual selection, with redder hair producing a favorable effect on the ladies?

It’s neither. Counterintuitively, orange fur acts as camouflage. Just as in the ocean, where the water absorbs all red light close to the surface, rendering red animals effectively invisible, so too does the vegetation of the forest canopy absorb red light first. Because orangutans travel in the lower levels of the canopy and the understory, below the tall emergent trees which filter out red light from the spectrum, their reddish coats actually make them hard to spot.

As for human redheads, science is still unclear as to what a diminished or increased tolerance for pain might have to do with anecdotal evidence about emotional instability and the libido. Until then, you can draw your own ill-formed conclusions. My investigation of aggression and reproductive vigor in orangutan communities has only taught me one thing: that redheads in the rainforests of Sumatra are effectively ninjas.

In other conclusions: Va va voom.