Who would have MHC genes that would compliment yours? Members of a population that underwent similar immunological pressures as your ancestors – but not exactly the same. Not a family member or close relative, but someone whose ancestors adapted to similar pressures created by the diseases that became so prevalent in crowded communities that were in close contact with each other and with the livestock they raised.
Pressures which began roughly 10,000 years ago, which is when our first blue-eyed ancestor was born and when racial differentiation began to emerge. And so it would make a certain amount of biological sense to be biologically compelled to make babies with members of our own race, to ensure that our kids have an immune system that’s suited to the immunological pressures they would have encountered:
”Body odor is an external manifestation of the immune system, and the smells we think are attractive come from the people who are most genetically compatible with us.” Much of what we vaguely call “sexual chemistry,” is likely a direct result of this scent-based compatibility.
And this compatibility isn’t outwardly expressed only in scent, we also wear our MHC genes somewhere even more obvious than our sleeves: directly on our faces. Multiple studies studies have shown links between the range of human MHC genes and facial appearance, as well as MHC genes and perceived attractiveness. It would follow that simply by looking at a member of another race, we would immediately know on an instinctual level that their MHC genes would be wildly dissimilar to our own.
Any examination of the National Center for Biotechnology Information’s online database reveals these disparities throughout our MHC genes. As this probabilistic selection of some of the HLA-A alleles illustrates, although some alleles occur at similar rates, the odds that many of them will occur varies widely across the MHC region of our genomes:
Each grouping represents a different HLA-A allele: 1, 2, 3, 11, 23, 24, 25, 26, 29, 30, 31, 32, 33
All of this makes a tremendous amount of sense, an instinct to create offspring with someone who is going to provide your child with the best odds of having a robust immune system would have been vital for any community that was under heavy pressure from disease. Although it’s important to keep in mind that this instinct would have begun to emerge 10,000 years ago, long before any sort of antibiotics or sterile surgery. Medical science develops incredibly quickly, even just 150 years ago doctors didn’t even realize they should wash their hands before jamming them up inside someone. Modern medicine has arguably rendered this instinct obsolete in practical terms, and yet it’s still wired into us as part of our primitive heritage.
But just because something’s an instinct doesn’t by any means make it Right. We also have instincts for violence and promiscuity that would cause our societies to implode if they weren’t regulated by human reason and rational decision-making. Human societies are epic practices in not embracing our basest instincts, individuals are encouraged to do their best not to act like animals. And yet all that said, it doesn’t make the instinct to breed with someone who’s going to provide your brood with the best suited immune system for the environment any less real, or any less a part of who we are.
So human females indicate a preference for mating with someone who shared a similar ancestry as themselves, but would it necessarily mean a distaste for outsiders? At least for ovulating women, yes it would.
Turns out women who are fertile exhibit a strong implicit bias against men from other races. While ovulating women were more attracted to men of their own race who were perceived as physically imposing, the opposite was true if the man was a member of a different racial group. So not only are we drawn to members who share a similar ancestry as our own, but human females are unconsciously repelled by members of other races when they’re fertile.
An increasingly common refrain in America is that it’s very easy to pretend that racism is dead and gone, at least until a black guy knocks on your door intending to take your daughter out on a date. This continued prejudice was dubiously enshrined in our laws against miscegenation, which were the last racist laws to leave our books and weren’t ruled unconstitutional until a generation after Brown vs. Board, at which point only 20% of Americans were in favor of legalizing interracial marriages. And yet despite that ruling, Alabama had a law against interracial marriage on the books until 2000, and even then 40% of Alabamians voted in favor of it.
African-Americans may be especially prone to be discriminated against, as recent analysis of the human genome has revealed that all non-African humans posses some Neanderthal DNA. And this DNA isn’t just random snippets, it forms an MHC allele that’s absent in Africans and would’ve boosted non-African immune systems as they traveled away from the continent.
Although women clearly have a much stronger sense of smell and are much more attuned to finding partners with compatible MHC genes, men are still aware of this interaction and their opposition to members of an outside race mate-pairing with sisters and daughters who share their genetic code makes evolutionary sense: they want their communal family gene pool to stay immunologically robust. Additionally, the apparent instinct of being able to smell and see a stranger’s MHC genes may easily have caused an instinctual xenophobia to develop, since someone with vastly different MHC genes would often be harboring pathogens that your immune system would be utterly defenseless against.
Because it’s not just fertile females who exhibit a prejudice against members of other races, recent research into implicit bias indicates that most white folks are unconsciously quite a bit racist. Research at Yale supports the idea that many whites are unconsciously biased, whether they admit it to themselves or not, and no matter how many black friends they have. The following experiments required a rather complicated set-up, but to get an idea of what your own implicit and unconscious feelings about race actually are, you can take a few minutes at: Harvard’s Implicit Association Racial Test.
In the first experiment, when white test subjects either read about or watched a video of a white guy calling a black man a “clumsy nigger” or saying “I hate when black people do that” after being accidentally bumped into, they frequently claimed they would have confronted the guy making the racist remark if they’d been there, and at least 75% of them said they’d rather work with the black guy in the scenario than the racist white guy.
But when subjects were actually in the room for the above event and the racial epithet was spewed in their presence, none of them actually spoke up and 71% of them said they’d rather work with the openly rather racist white guy than the black man. But it gets a lot worse, as demonstrated by one recent study conducted over the course of six-years at Stanford:
…that showed [white] study participants words like “ape” or “cat” (as a control) and then a video clip of a television show like “COPS” in which police are beating a man of unknown racial identity. Then, the researchers showed the participants a photo of either a black or white man, described him as a “loving family man” yet with a criminal history. They then asked participants to rate how justified they thought the beating was. Those who believed the suspect was black were more likely to say the beating was justified when they were primed with words like “ape.”
Leading researchers to the uncomfortable conclusion that “whites subconsciously associate blacks with apes and are more likely to condone violence against black criminal suspects as a result of their broader inability to accept blacks as ‘fully human.’” But all of these subjects were at least college-aged, perhaps nothing instinctual is going on and they’re just displayed culturally learned behaviors. Well, if that were the case – why are nine-month old babies racist too?
Turns out white nine-month old babies with little or no previous contact with African-Americans have trouble telling black faces apart and don’t register emotions on black faces as well as emotions on white faces:
“These results suggest that biases in face recognition and perception begin in preverbal infants, well before concepts about race are formed,” said study leader Lisa Scott in a statement. The shift in recognition ability was not cultural, rather a result of physical development.
Although, curiously, five-month old babies seem to process faces from either race the same way. But it’s important to note that babies don’t develop a fear of height or a fear of strangers until they’re seven-months old. Five-month old babies might seem to be processing “faces” of different races the same way, but without a fear of strangers it’s a bit hard to argue that their brains have developed to the point where they can understand the concept of personhood in the first place. And without any fear of height it would seem their brains haven’t yet reached the point where any fear instinct at all would have kicked in.
Plenty of research has been done into racism as a cultural reality, but very little if any at all has examined it as a naturally occurring instinct that’s inexorably rooted in our biology. And even if you haven’t been on X-Box Live or an internet messageboard recently, if you take a moment to look at the data it become readily apparent that American society is still unarguably organized largely along racial lines:
- Only 14% of all illicit drug users are black and yet blacks make up over half of those in prison for drug offenses
– A black child is nine-times more likely than a white child to have a parent in prison
– A black man is eight-times as likely as a white man to be locked up at some point in his life
- The average black family has eight-cents of wealth for every dollar owned by whites
- Blacks are more than three-times more likely than whites to have their home foreclosed and be thrown out into the streets.
What if the policies that have created these abject discrepancies aren’t simply a result of learned cultural behavior, but are in fact deeply rooted inside of our genome? If an aversion against members of outside racial groups is fundamentally rooted in our biology, and not culture, the fundamental interaction of societies with mixed racial groups and the policies they enact should be very carefully reexamined.
In a perfect world our children would be judged by the content of their character, but if the color of their skin is linked to a subtle unconscious instinct for racism within each and every one of us, we aren’t going to get anywhere until we bring this viscous racial chimera out from its genomic cave and deal with it directly.
“Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity”
- Dr. Martin Luther King Jr.
Category: Africa, anthropology, biological racism, genetic compatibility, genetics, human genome, human migration, immunology, impact of agriculture, MHC genes, racial tension, racism, smell a mate, war on drugs | Tags: genetic compatibility, genetics, MHC genes, news Comment »