Thanks to technological advances in the last few years, scientists are now able to sequence people’s genes. In my previous post [11/18/07 - I highly recommend reading the previous post, it's much better than this post, but the NY Times linked to this one for some reason] on race and intelligence, I pointed out that scientists have already discovered genes that correlate with higher intelligence as measured by IQ tests (for example: link1, link2). I wrote that soon we will be able to determine if the high intelligence version of various genes occur with greater or lesser frequency in the gene pools of the different races
It was pointed out in the comments that we already have a way to determine this! There exists a publicly available gene database, The HapMap Project, that contains random samples of genetic sequences from people in China, Japan, Nigeria, and people in the United States with European ancestry. It’s now possible to search the HapMap database for genes that have been linked with intelligence in published scientific studies. In this manner, we can determine if high intelligence genes occur with greater or lesser frequency in the various races.
Now, here’s an interesting point. If even a single gene correlated with intelligence occurs with different frequencies in the different races, this alone proves that there are racial differences in intelligence. How is that? Well, the egalitarian theory holds that every race has identical intelligence. Therefore, whatever genes there are that affect intelligence, they must be distributed exactly equally in all human races. Once even a small race difference is proven, the egalitarian theory is proven false. At that point, it’s only a matter of determining which race has the higher average intelligence based on the genetic evidence.
I have to confess that I currently don’t know how to use the HapMap database. Thus it’s impossible for me to determine if the following comment by “Marc,” about the DTNBP1 gene is true or false:
Let's look at rs:760761, rs:2619522 and rs:2619538, all of which are associated with increased or decreased intelligence in DTNBP1.
Regarding rs:760761, 18% of Europeans carry the T allele, which knocks about 8 points off the ol' IQ, compared to around 7% of East Asians and 37% of blacks.
Regarding rs:2619522, the numbers are similar. 18% of whites carry the G allele, which knocks about 7 points off the ol' IQ, versus around 8% of Asians and 35-36% of blacks.
Regarding rs:2619538, 39% of whites carry the A allele, which adds about 6.5 points to one's IQ, versus about 99% of Asians and 31% of blacks.
[UPDATE 11/16/07: I did the above calculations with more detail: DTNBP1 gene and racial IQ differences.]
Marc seems to be saying that there are statistically significant differences in the DTNBP1 gene in the different races. Thus, for the very first time in the history of the study of intelligence, we have actual proof that the races do not have identical distributions of genes that are correlated with intelligence.
Here’s another interesting fact about the DTNBP1 gene. This gene is also associated with schizophrenia. James Watson’s son has schizophrenia. James Watson obviously knows about this research because this is his field of expertise and he has a personal interest in schizophrenia. He probably knows about the HapMap project also. When he said there are race differences in intelligence, he based this on personal knowledge of the very latest genetic research.
Will this information convince anyone of anything? Even before genetic sequencing, we knew of at least one gene correlated with intelligence. That’s the gene for myopia. There have been many experiments conducted around the world, all showing that high IQ is a risk factor for myopia, independent of the amount of reading one does. Take, for example, this recent study . Before genetic sequencing, we knew that myopia was highly hereditary based on the usual kinship studies (children have myopia if their parents have myopia). And we also knew that myopia occurs with different frequencies in different populations. Jews and Asians have the greatest prevalence of myopia, non-Jewish whites in the middle, and blacks have the least prevalence of myopia. The distribution is as expected. The smartest races have the greatest prevalence of myopia. The distribution of myopia proves, even before genetic sequencing, that there are definitely genetic race differences in intelligence. Even though there is rock solid scientific evidence that the races are not genetically identical when it comes to cognitive ability, the left-wing anti-free-speech deniers just hold their hands over their ears and scream “racist” at anyone who speaks the truth.
The myopia gene is also an example of how a genetic variant can have both a good effect and a bad effect. All things being equal, it’s always better to be more intelligent than less intelligent. A gene that causes high intelligence but has no detrimental effects should appear with high frequency in all races. So when natural selection favored Europeans and Asians for higher intelligence, it must also have disfavored them in other desirable attributes. Good vision is but one example. (If you’re still interested in myopia, the latest research shows that there are two genes, PAX6 and SOX2, associated with it. At least one of those two genes probably has something to do with IQ.)
If it is true that natural selection favored higher intelligence in Asians and Europeans, we will probably find that for the vast majority of genes correlated with intelligence, the more intelligent variant of the gene will occur with greater frequency in Asian and European populations. The exception is genes that cause lower intelligence but nevertheless confer a unique survival advantage to Asian and European populations. Imagine a hypothetical genetic variant that causes both lower IQ but greater protection from the cold weather. This gene is useless to Africans living in the hot jungles, but valuable to northern people dealing with cold winters. This is an example of how a gene might buck the trend and appear to disprove the hypothesis that blacks are less intelligent than Asians and white. Unfortunately, those who dispute the race-based theory of genes and intelligence will scream loudly about these types of genes (even though, by pointing them out, they admit that genes influence intelligence and that such genes are not equally distributed among the races).
"Marc" offered the following correction:
Dude, you didn't post my correction regarding rs:2619538. (Maybe I hadn't made it yet when you were posting, though.) I got my alleles mixed up. Actually, 69% of blacks had the allele that correlates with the *higher* IQ, versus 31% of whites and only 1% of Asians. When you calculate the sum effects of the four alleles using the hapmap data, it leaves blacks with an IQ deficit of 3.6 points relative to whites (the boost they get from rs:2619538 doesn't entirely make up for the distribution of the other alleles) and whites and Asians are nearly equal, with Asians having a deficit of .2 IQ points relative to whites. Having said that, I got to say, once the gentle euphoria of "discovery" wore off, I realized that this doesn't really prove anything. I don't even know how many, if any, of the studies tying these alleles to intelligence have been replicated, and all the studies I've seen suggest that there may be as many as 50 alleles coding for intelligence, if not more. Still, it was a fun exercise, and I do think that as more alleles are identified (and verified) we will be able to get a much more complete picture.
In response to whether it proves anything, it proves that alleles associated with intelligence don't appear with the exact same frequencies in each race, as the left-wing-egalitarian theory insists upon. In fact, it's quite a big variation.
The assertion that the races are exactly equal in genes that effect brain functions has been proven false.
This blog post has been linked to by the New York Times. My initial response to that article can be read here: Half Sigma in the New York Times.
For those who wish to read the blog post by Jason Malloy that was mentioned in the NY Times article but without a direct link, here is the link: James Watson tells the inconvenient truth: faces the consequences.
I've written an additional post, Response to comments on race and intelligence, where I respond to the most common comments.
A blogger whom I presume to be Indian (thus not a racist trying to prove white superiority) has a blog post summarizing the various genes that have been discovered that are related to intelligence, as well as comments regarding how they vary in frequency in different races.
The best blogospheric proof yet that races are not genetically identical in average cognitive abilities.