A reader sent me an email about some arguments put forward by race realists, told me he did not know a good way to refute them and asked me for my take on it. I am not convinced he is a concern troll, but some of the language he used and the fact that the quotes of his opponents cannot be found on the Internet makes me suspicious. However, because it is so hard to tell, I will try to be charitable. The person asked not to have his name posted, so I will just refer to him as “he” or “the reader” below.
Hey there. I found your blog a month or two ago when I started researching the topic of racial IQ differences. Lately, I’ve been debating some people over the internet about this subject using some of the information that you and other egalitarians have provided. As expected, the folks who I was talking with didn’t like what they heard and responded with ad hominem attacks, but there was one point someone brought up that I simply couldn’t respond to.
For me, phrases that stand out here are “racial IQ differences”, “you and other egalitarians” and “one point someone brought up that I simply couldn’t respond to”. The first phrase is suspicious because it associates race with IQ difference, when most individuals who reject race realism thinks that most observed differences are due to other factors besides race. Furthermore, “egalitarian” is a word that reminds a lot about “Darwinism”. It has its uses, but most of the time, it is a concept that those opposing it use to try and make the science-based position appear as if it was an ideology. Finally, The last phrase reeks of concern trolling.
This is not an iron-clad case and we should welcome actual concerns. Also, it is important to respond to the point brought up no matter if the person is a concern troll or a person who has a legitimate question.
The point he “simply could not respond to”
The argument he had trouble with was:
Because it is late and I’m very tired, I’ll just copy and paste what they said: “So you’re going with the “Society discriminates against blacks based on skin color even when they’re raised in white, middle-class families” argument? How do you explain the intermediate IQ scores of mixed-race individuals? They’re not just intermediate, they’re proportionate to racial makeup. Say that an IQ of 85 is 0 on our scale, and an IQ of 100 is 15. The black mean is 85, so 0 on our scale. The white mean is 100, or 15 on our scale. The mean for individuals who are half black and half white is about 7.5 on our scale. For individuals who are one quarter black and three quarters white, it’s about 12 on our scale, or approximately 3/4 of the way from the black mean to the white mean. How do you explain the precision of this relationship? Do you put forth that society discriminates against mixed-race individuals based on their skin color with this level of precision? Don’t you see that that’s preposterous?”
Blending inheritance versus meiosis
A very common belief about race realists is blending inheritance. It is a position that existed before the advent of genetics and asserts that the genetic contribution from parents mixes randomly and the offspring always has some intermediate phenotype. The problem is that this would mean that the genetic variation would decrease substantially in just a few generations (leading to the absurd belief that the genetic structure of one ethnic group could be “diluted” by producing offspring with someone of another ethnic group), but we know today this is not the case.
Instead, this perspective has been replaced by meiosis. Concretely, this means that a child to one parent who is “white” and one who is “black” does not need to have precisely the intermediate IQ.
“1/4 black” is a claim about genealogy, not genetics
The argument uses terms like “white”, “black”, “half-black, half-white” and “one quarter black and three quarters white”. I do no really find these meaningful from a scientific standpoint, but will use them to make a point (keeping them in scare quotes).
The argument uses phrases such as “one quarter black and three quarters white” as if “black” and “white” were alcoholic beverages that you could mix. This has nothing to do with genetics, but about genealogy. Being “one quarter black and three quarters white” means that you have one grandparent that has been categories by society as “black” and three grandparents that have been classified as “white”. But this does not mean that your genetic constitutions are “one quarter black”. Why is this?
Let’s use a cake analogy. Imagine that you have one chocolate cake and one vanilla ice cream cake. Now, take half of the chocolate cake and half of the vanilla ice cream cake and put them together. You now get a cake that is half chocolate, half vanilla ice cream. This represents having a European-American mother and an African-American father. During the production of gametes, only half of the genome will be transmitted (so the offspring will have just one genome, instead of two). So lets cut our new cake in half. How do we make the cut? We could make it across, making so that the new half of the mixed cake is 1/4 chocolate and 1/4 vanilla. But we quickly realize that we can make the cut anyway we want as long as it represents 50% of the mixed cake. So, for instance, we could cut it just between and have one half be 2/3 chocolate and 1/3 vanilla. This is how the situation works genetically.
While you do have 50% of your genes from mom and 50% from dad, it is not guaranteed that those 50% from dad contains 25% from his dad and 25% from his mom. The distribution of alleles from grandparents and further back is subject to stochastic variation. This is obvious, since if we go back far enough we would have gotten less than a nucleotide per great-great-great…-great grand parent.
In other words, there is no reason to suppose that the person who is “one quarter black and three quarters white” would have half the amount of “beneficial IQ alleles” (whatever those are) compared with someone who is “half black, half white”. Stochastic variations mucks it up.
In other words, the supposed discovery that people who are “one quarter black and three quarters white” have an intermediate IQ between “blacks” and people who are “half black, half white” does not make any sense even assuming race realism.
By the way, the claim that people who are “one quarter black and three quarters white” have a different IQ than “blacks” is wrong. An impressive adoption study by Elsie G. Moore (Moore, 1986) done in the 1980s showed that there was no difference in IQ between “black children” and “mixed children” being adopted by middle-class “white” families. So even the basis of the argument is flawed.
Another race realist assertion bites the dust.
Inheritance does not blend. Proportion of genes from grandparents and up are subject to stochastic variation, so “one quarter black and three quarters white” is a genealogical term, not a genetics term. The claim that “black” and “mixed” have different IQ is wrong.
Moore, Elsie G. (1986). Family socialization and the IQ test performance of traditionally and transracially adopted Black children. Developmental Psychology, Vol 22(3), 317-326. doi: 10.1037/0012-16126.96.36.1997
Nisbett, R. E. (2007). All Brains Are the Same Color. New York Times. Accessed: 2012-11-24