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Rhinocrisy

06 February, 2006

Black people are better at everything

A completely Super-Bowl-unrelated conversation led me to this rather old Salon article by Gary Kamiya, titled "The black edge: Are athletes of African descent genetically superior?"

The article is a review of a book by one Jon Entine, titled "Taboo: Why Black Athletes Dominate Sports and Why We Are Afraid to Talk About It". Entine, while bowing low to acknowledge that training and opportunity and hundreds of other environmental and social factors contribute, argues that blacks essentially do have better genetics.

This may be true, but I think this is something of a fallacy. The key lies in the brief parenthetical given by Kamiya, "Africa has greater genetic variety than any other continent, which helps to explain why people of African descent can be genetically gifted."

The above is a very well-established fact and is the product of the famous "Out of Africa" migration ca. 100,000 years ago, which forced a population bottleneck. The Out of Africa population had to undergo a dramatic contraction and expansion in population size, which has the effect of removing significant amounts of genetic diversity from the population. Subsequently other populations underwent additional bottlenecks - upon migrating into Europe or East Asia, for example. We can see the signature of these bottlenecks in the distribution of gene frequencies in these populations.

If we consider new and frequent alleles (that is, those that arose after our divergence from chimp and that show more than, say, 5% frequency in the population), which are more likely to be under positive selection than new rare alleles, then there will be almost no alleles present in Out of Africa populations that are not present in the African populations. Actually, this will be sharper for genes under selection, since selection should be weaker in bottleneck populations.

What this means is if we consider any particular trait that confers some freakish ability, we should expect to find Africans with that freakish ability. This will increase further if we consider multi-factoral traits, since it's far more likely that we'll find the coincidence of two alleles in an African population than we will in an Out of Africa one.

This has only one meaning: genetic diversity is VERY good for populations as a whole. This ought to apply to any sort of trait, not only athletic prowess, so really we should expect to see black luminaries dominating in all sorts of endeavors. So why don't we? Well, obviously some things have stronger environmental components than others. It's easy to pick up running. All you need are feet. Picking up the violin, on the other hand, is a tad different, and historical and social factors will obviously have much more weight there. But as that violin-playing field levels out, if genetics matters we should expect to see Africans dominating there.

As a final note, remember this: marry someone as genetically distant from you as possible. Can't hurt.

Comments

Interesting article. Just to play devil's advocate, and because this argument is inherently troubling, I'm going to offer the following critiques.

1) The race analysis, while more nuanced than I thought it would be, is still pretty lackluster. From what I understand, Blacks in the U.S. are rarely, if ever, solely inheriting African genes. Further, the use of "Whites" "Blacks" and "Asians" as the three main "races" is part of a tradition that has a long and sordid history--that the article taps into, imo, despite referencing parts of it. You can make the argument that Black people are a cultural and socially coherent group, but genetically? related to athleticism? I want more evidence, given the "one-drop rule."

2) I'm reading Mismeasure of Man (Stephen Jay Gould) right now (fabulous book). I saw that the article does mention the long history of interpretation of different factors and their relative weights in understanding various racial groups and how that ties into racial stereotypes. Given that the thesis of this book neatly ties into longstanding cultural and essentialist stereotypes of Black people as physically stronger, not designed for intellectual activity, blah blah blah (despite what the article says to the contrary), I would like to see hard data that not only proves that this is the case, but additionally explicitly spells out the methodology of the scientists referenced and the key assumptions they made. Otherwise, it would be hard not to reject it out of hand given that the author of the article is a layman and the Entine is a sports journalist. Not to be elitist, but neither would seemingly have demonstrated expertise in evaluating the genetic  arguments (at least that I know of from the article) and ideas like this are too fraught with implications to play around with a lack of rigor.

All that said, of course it's possible that the guy's right--it's just that there's a much stronger burden of proof on the author. 

Posted by Saurav


There's of course no such thing as a genetically coherent racial group. Lewontin has a famous paper about this from back in 1972, demonstrating that the amount of shared genetic variation in the human population vastly exceeds the amount specific to any sub-group.

As to "blacks", you're right about African-Americans - there's a lot of genetic intermixing of African and European ancestry there. (This means for me it's preferable to work with data from a relatively pure African population, since there's no strange population structure/migration issues munging up your population genetics.) But that's more or less immaterial to the point I was making, which was merely that individuals from genetically diverse populations are, being more diverse, far more likely to show up when looking for any particular trait that you don't suspect would be population-specific (like skin color). This (greater genetic diversity) is probably still true of black Americans compared to white Americans, and it's definitely true of Africans compared to Europeans or East Asians.

This is different than the argument Entine is making, which is that there's some specific population-specific traits that make, say, West Africans better athletes. Far more akin to a traditional race argument.

Anyway I could go on for ages about race and genetics - I'm late for work. 

Posted by saurabh


over the summer i read a fabulous article that someone copied from a musicology book about the issue of ethnicity in the americas. ("ethnicity: ethnic quality or affiliation." not your provable background, but that which you take or is thrust upon you.)

ethnicity is used to define borders among the music traditions in the americas; tracing the growth of these traditions and their ethnic affiliation is probably more complicated than determining human ancestry because the history can be forgotten to the point that in some places there is music that is "traditional" and nobody has any idea how it got there or what purpose it served way-when. (this is true of reggae.) however throughout the americas there is white music, black music, native music, and a variety of popular mixtures. south asian blends are particularly popular and predate bhangra - in this hemisphere they started in trinidad.

this is an interesting nature-nurture question. "white folks can't dance" is the question. the difference in what the community considers high music, and how that high music is structured, is such a big difference and exposure starts so early that if you wanted you could make stupid arguments that a sense of rhythm is inherited.

personally i think nature/nurture needs a third leg so it can stand on its own: plunder. the kid is wired to steal cultural material up to and beyond the point where it can live on its own without getting kicked out of society (because in society you can share labor, get laid, learn jokes, and eat better food, and the divine forces want us to have these things).

anyway i would make it a third category because nature and nurture make it sound like the line should be drawn between fully-functioning adults making sensible choices, or cockfighting.

as said the divisions of groups in the united states - white, black, hispanic, asian, and other - are stupid and bear little more than superficial scrutiny. within each of those are divisions larger than among them. most of the differences can be filed under differences in religious practice. dividing us by catholic, protestant, muslim, jew, buddhist, hindu and other makes much more sense.

i guess i'm throwing this in to help eliminate a few "not genetic" items from the list. 

Posted by david


("this is true of reggae" means that those parts of jamaican music not easily traced to rhythm & blues can't be traced very far back because there are no written records of jamaican african folk music basically from before 1950 and no recordings. the music didn't leave the ghettos and nobody knows how the 1950s styles came to be. this is my understanding. in fact, possibly connected to this, there are few reliable records concerning who besides the english even lived in jamaica.) 

Posted by david


Sorry--I should have been more specific. I was addresing my comments to the article on Entine's book, not directly to the points you were making in the post about genetic diversity. 

Posted by Saurav


Thought you may be interested in this comprehensive dissection of the article:

http://www.kenanmalik.com/reviews/entine_taboo.html 

Posted by Rohin


"black" success in american professional sports - it's silly to call this a physical thing alone. at the top level of a sport, physical capabilities are pretty well matched. what often distinguishes top athletes from others is their tremendous analytical and visualization capacities, applied particularly to developing rhythm sense and to refining response time. being fast or strong or whatever is central to getting into the game, but to win the game, you have to be able to fake people out.

enjoying head-to-head versus solo competition - including how you see what your job is when playing a group sport - is another aspect.

regarding "out of africa": article and discussion . 

Posted by david


Actually, this will be sharper for genes under selection, since selection should be weaker in bottleneck populations. 

well...the power of selection relative to random genetic drift decreases as the population size decreases. ie, it isn't like the probability of selection via fixation, 2 X selection coefficient, for an advantageous allele, decreases as you scale effective pop size up or down. but, the probablity of fixation for neutrality does increase a lot (1/(2 X effective pop). in other words, keep selection constant, but shift drift.


What this means is if we consider any particular trait that confers some freakish ability, we should expect to find Africans with that freakish ability. This will increase further if we consider multi-factoral traits, since it's far more likely that we'll find the coincidence of two alleles in an African population than we will in an Out of Africa one.


hm. well, depends on if it is neutral, right? if being super pale is "freakish ability," well, africans are highly constrained don loci like MC1R. europeans have 30 loci > 1%.

This will increase further if we consider multi-factoral traits, since it's far more likely that we'll find the coincidence of two alleles in an African population than we will in an Out of Africa one.

well, if it is a totally random variable...but selection can drive the mean frequency of an allele over and make the variable...less random, so to speak :) diversity is good, ie variance, but if you shift the median on a normal over then you get LOTS more on one particular tail, right?


As a final note, remember this: marry someone as genetically distant from you as possible. Can't hurt.


might, actually  :) (i think this is a exception to the rule, nevertheless, the genome is a big sample space) 

Posted by razib


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