I believe the essay to which iiandyiiii keeps referrring is this one.
That essay does not itself contain any cites, but purports to lean heavily on the book by Jencks and Phillips called “The Black-White Test Score Gap.” The copy I own of that book was published 1998.
Chapter 3 is “Race, Genetics and IQ” and lists a number of references, some surprisingly old. (e.g. Martin Jenkins, 1936, “A Socio-Psychological Study of Negro Children of Superior Intelligence” in Journal of Negro Education). In my opinion the chapter is a bit of a hodge-podge and does not really get at the core question of whether or not there are gene prevalence differences by SIRE groups. Studies are presented uncritically. For example, the post WW2 German/Black GI children IQ study is given as supporting evidence of no genetic differences without mentioning that the black GIs were a highly selected, non-representative subset, 60% of whom scored in the upper half of the mental ability test (versus 14% of the black male population in general at the time).
The paper addresses “inferred Darwinian selection” to try and decide the basic question of whether gene prevalence differences arose from simple population bottlenecks (for example) or because of positive selection pressure. Their conclusion is that many alleles were positively selected for. They compared african, european and asian subgroups.
*“We outline several predominant biological themes among genes
detected with this strategy and suggest that selection for alleles in
these categories accompanied the major ‘‘out of Africa’’ population
expansion of humankind and/or the radical shift from hunter–
gatherer to agricultural societies.”
“The model that
best explains these data is the ongoing balanced selection for these
alleles for at least the last 40,000–50,000 years after the out-of-
Africa expansion.”*
The biological themes of the selected genes (see figure 5, p. 139) are in the ontological categories of:
*“…pathogen–host interaction, reproduction, DNA metabolism (including putative transcription factors), cell cycle, protein metabolism,
and neuronal function.” * (emphasis by CP)
So…genes are positively selected in these populations for at least six ontological categories, one of which is “neuronal function” and you want to argue repeatedly “there is no genetic evidence.” Is it the case that you think these sorts of genes are positively selected for some reason other than being advantageous?
In the case of genes for neuronal function, what might that advantage be driving the positive selection?
As opposed to your supposed lack of a bias? That’s a laugh.
Again you make the weird implication that every single heritable characteristic must vary by population. There’s no evidence for this sweeping claim.
I’m not going to get into the weeds of specific genes (we all recognize that it’s porbable that heritable intelligence factors from an unknown, but probably very large, number of genes) until we’ve identified (at the very least) and confirmed the majority of genes relating to intelligence and their prevalence in different populations.
If something varies between populations, then a hypothesis can be formed (in these cases the “genetic explanation” hypothesis) to try and explain it. In order to test this particular hypothesis, there are two strategies- find the genes and demonstrate their link to the characteristic and their different prevalence in different populations, or eliminate all possible non-genetic explanations. I think the second is essentially impossible, considering the huge varieties of human behaviors and cultures, without a biosphere-type experiment, so I think the only way to test this hypothesis is to find the genes. Until the genes are found there is no reason to support this hypothesis. Frank Sweet’s explanations (or hypotheses) of a combination of lesser parenting skills (for the youngest children), lower teacher expectations (for young school-age children), and “oppositional culture” peer pressure (for adolescents) can also be tested for (with difficulty)- and while these are, at the very least, hard to quantify, there’s actually lots of evidence for lower teacher expectations (for example here and here) and lots of studies about the unquantifiable “oppositional culture” (here and here, for example). These have positive, direct evidence- unlike the genetic explanation. Your incredible confidence in the genetic explanation requires you to believe in a conspiracy among the major institutions of the various related fields (like the research journals and professional organizations), none of which support the “genetic explanation”. So not only do I find your explanation free of evidence, I find your certainty that such a conspiracy exists to be ludicrous. You are, sadly, just the latest examples of a dying breed- the pseudo-scientific racialists (or race-realists, or whatever)- who have insisted for more than a century that some races are inherently inferior in intelligence, aggression, etc. The claims and methods have been refined- Jews and the Irish, for example, have been shuffled around in the made-up “racial hierarchy”. The one aspect that has remained the same is the insistence that at the bottom of this hierarchy lies black people. It used to be such ridiculous “evidence” as skull shapes, and now it’s the more respectable-sounding trappings of modern science, though you still can’t hide the complete lack of evidence for the genetic explanation. The test-score gap has existed for a few decades, and has even shrunk by some measures. Why should I believe it’s immutable? It’s just ridiculous to claim that all the efforts that might eliminate have already been made- especially considering the many instances of systemic, institutional discrimination that continue to exist.
There is no evidence for the genetic explanation, and it doesn’t fit all the facts. There are other hypotheses that, at least, have the virtue of fitting the facts, even if they have not been confirmed.
Whether or not these genes are positively selected for offers no evidence for different prevalence among different populations. You continue to imply that every single human characteristic with a heritable component must then vary by population. I find this a truly strange claim to make.
I misunderstood the claims of this paper in my first reading. It still offers no evidence for differences in genes for intelligence between populations- it just says that there may be some selection in some gene differences among different populations that may be related to neural function. I can’t see any claims about what neural functions, or whether these are related to intelligence, so it offers no support for your hypothesis. Zero evidence for the genetic explanation.
What it says is that the differences in genes–including the category of neural function–is due to positive Darwinian selection. This is a significant difference from mechanisms such as a population bottleneck. It means nature finds those genes advantageous ones.
Is it your position that there is zero evidence for a genetic explanation of brain differences among human populations even though I have just given you an example of a paper showing that mutated genes underpinning neural functions are driven positively by evolution?
How would low teacher expectations and oppositional culture explain the abysmal performance of HBCUs? How would it explain crappy MCATs and LSATs? Are populations of students performing at the level that would let them apply to Law and Med school so malleable to these forces that they literally cannot learn material? How about if we look four years further on at the post-med school exams used for residency application? What about if we look yet further on to the success rates for passing specialy board exams in medicine? When does this effect end, and why is there such a pervasive pattern across the world, whether the population demographics put a SIRE group in the majority or minority?
How would either of these explain what every employer sees repeated as a nearly universal pattern: On employment exams, with a defined body of information to learn, the pattern of asian on top and black at the bottom is going to persist, even if you hire outside consultants to carefully craft the test in order to make sure it is race neutral? (See for example, the New Haven Ricci v DeStefano case, or any large-city police force trying to screen applicants)
Oppositional culture and teacher expectations don’t even begin to pass a sniff test. They are nearly all simple studies or collections of anecdotes filtered out for confirmational bias.
Given that it’s what most of the past 300-odd posts seem to have been about:
Why is it so important to be able to say that genes cause the members of certain socially-defined groups to score marginally higher/lower on particular types of intelligence testing?
Why does it matter how the larger cortex came into being? Whether it was due to some random gene event a hundred thousand years ago or was due to the pressure put on the population to be also to survive in such a barren area, it seems, from the report, to be something Aborigines now share. No?
The only way I can see your point mattering is if you thought that the visual cortex in Aboriginal babies were the same size as the VC in Caucasians, etc. Is that your position? If not, why doe how the VC got larger matters. Barring the possibility that the cortex gets larger after birth, due to environment, how does it differ from there having darker skin, genetically?
Because some people assert, explicitly or implicitly, that “the gap” is solely the result of discrimination and other environmental differences and that in order to close the gap, massive amounts of societal resources need to be expended and there needs to be discrimination against members of higher performing groups.
That paper does not say that any population has “superior” genes or function (that I can find). It doesn’t link any particular genes to intelligence- just to neural function. And there is no evidence that the presence or absence of these neural-function genes has any correlation with higher or lower intelligence. So no, this paper offers zero evidence for the genetic explanation for the test score gap. Zero. Nothing. Zilch.
Your own biases make it impossible for you to reasonably judge such things. Sweet’s hypotheses fit the facts, and actually have positive evidence in support. Your genetic explanation has zero evidence. No evidence, nothing.
I was not aware the study you cited was about babies- I thought it was about older children. If newborns have different visual cortex sizes, then that would eliminate some of the “increased usage”-type hypotheses. I wonder if such studies have been done.
Diamond does not support the genetic explanation at all. It’s quite convenient how you take tiny pieces from researchers who oppose your explanation and ignore all the rest.
I’ll explain again how science works (in my understanding). A question is formed- in this case “what is the cause (or what are the causes) of the test score gap?”. A hypothesis is made- in this case, some say “the best explanation for the test-score gap is, on average, different genes for intelligence in different populations” (essentially “black people are inherently genetically dumber on average”). The data that shows the test score gap says absolutely nothing about why the gap exists- one needs to gain additional data. And additional data that shows the test score gap provides nothing for answering this question.
That’s as far as the pro-“genetic explanation” crowd has proceeded- they’ve made a hypothesis, and that’s it.
In order to test this hypothesis, there are a few things that could be done- I’ve made the suggestion of a bio-sphere-type experiment in which multiple populations are raised from birth in a completely controlled society that is 100% free of any sort of racial bias (from media, cultural attitudes, individual prejudices, etc.). The logistical and ethical challenges probably preclude this kind of experiment. So we’re left with finding the genes, because there’s no other way of eliminating every other possibility. Not a few genes for neural function (which may or may not have anything to do with intelligence), not a few genes for brain size, not a few genes for brain development, but all (or at least the large majority) of the genes responsible for intelligence- and then a broad survey that shows different populations with different abundances of these genes, and a direct correlation of the presence of these genes with intelligence. Science is hard- and from what I’ve read so far, the opposing side of this argument doesn’t really understand how science works.
I don’t know. And I didn’t men to imply that the study was bout newborns. But you seem to agree that if such a study revealed larger VCs in newborn Aborigines, that that would mean that genetics were at play. Correct?
Now how about if the study looked included Aborigine children who had not been raised in the traditional environment. Let’s say it included 100 kids living in the Outback, 100 Aborigine kids born and raised in New York City, 100 kids raised in Sicily, 100 Aborigine kids born and raised in Brazil, etc., and the results found that all the kids had the same size VC, would that satisfy a genetic hypothesis?
No, it could still be environmental (like pre-natal nutrition, pollution, or something else). But it eliminates a lot of environmental explanations. I wouldn’t deny the genetic explanation in that case, but until there’s actual genetic evidence (or some other sort of evidence), we can’t say what the explanation is.
[Edited after another reading of the post] That would probably eliminate a lot of the environmental explanations. Certain environmental explanations can be eliminated in various circumstances, but not all of them at once, unless the genes happen to be found.
This is what makes “debating” you so frustrating. You cannot seem to stick to a point or to understand what the other person is saying.
I realize that John Diamond, who is black, probably does not support a genetic explanation. I gave this link to you as an example critique of the way-overhyped Ogbu “oppostional culture” excuse, and I did not label it as a genetic explanation.
I am underwhelmed at the oppositional culture explanation, and I find it a rather insulting one. We cannot choose our genes, but we can choose how we respond to environment and the idea that the entire black population is a special victim of oppositional culture is demeaning, in my opinion.
But, as Diamond notes, the real problem with the hypothesis is that there simply isn’t any real evidence that blacks are somehow particularly disadvantaged by “oppositional culture.”
Unlike you, apparently, I sort through any and all comments from any and all authors, and it’s true I make my own decisions about which points resonate and which do not. For what it’s worth, the anti-oppositional culture position he takes is not a “tiny point” but rather the thrust of his entire essay.
I can’t say that I’m not pleased by this, coming from you. I’m very happy to frustrate those who hold to conclusions without scientific basis.
How about the (evidence-free) idea that the entire black population is genetically inferior, intellectually? I really don’t understand how your mind works, not that this will surprise anyone.
I gave this link to you as an example critique of the way-overhyped Ogbu “oppostional culture” excuse, and I did not label it as a genetic explanation.