Heritability is a meaningless value in intelligence studies. And the heritability of height tells you absolutely jack all about any potential underlying genetics for intelligence, even if the numbers are exactly the same.
Again, you are doubling down on the ignorance, surveying experts in other fields about what the genetic evidence was is only a formula made by people that want to press for a controversy that is not really there,
Once again here is a good explanation from science writer Peter Hadfield:
It is also dealing mostly with climate change deniers, but it does apply to the big flaw that the ones making that survey ran into. Having expertise in one field does not make one an expert in others.
the fact is that even you have to resort to grasping at straws like that survey because there are no easy pickings even for your claim that most of the experts would agree with your claims.
And yeah, even your latest link there is pointing that no one has tested that reported gene that makes a difference with the intelligence among races. In light of the recent evidence I have to say that just as in many other examples there is no specific gene that makes the difference in intelligence, but a collection of them and it is very likely that environmental factors do affect the mix so strongly that it is not really a good idea to then use mostly a genetic framework when societal solutions are being considered.
Indeed, I’m simply pointing out that they’re both quantitative heritable traits. And the same researchers (eg Visscher et al) have used the same technique to show cognitive ability is also a heritable trait is accounted for by numerous genes of small effect.
Are the variants likely to occur in identical frequencies across populations? It’s possible, but people like MIT Professor Robert Weinbergseem concerned they won’t. As I noted above - given groups differ in basic areas like brain shape and size it does seem a valid concern.
Cite?
You can compare here controlled for parental income and parental education levels.
And I’m pointing out that that’s a meaningless point. Lots of traits are quantitatively heritable (and it’s highly questionable whether intelligence is one of those; at best, I’d grant it “qualitative” status). That does not mean they are in any way associated, or that the genetic underpinnings are similar, or that any such traits will respond similarly to selective pressures, or anything of the sort. The heritability of height, no matter what its value, or how it’s measured, has nothing whatsoever to do with intelligence studies.
Pure speculation on all counts. As noted previously in your cite, any genetic basis for intelligence remains unknown.
No, it isn’t. That’s pretty much the whole point and definition of heritability – and a limitation thereof: the heritability of a trait (any trait) applies only to a given trait in a given population at a given time, and is in many cases at best an estimate. It is not a fixed value, applicable across a species, or even necessarily across populations within a species. Weinberg’s “concern” is nothing more than an observation - of course different alleles will vary within and between populations. So?
So that may help explain group differences in phenotype - isn’t that the concern? That’s what Hsu identifies as the dangerous possibility:
Given that differences in IQ/intelligence haven’t yet been demonstrated to be phenotypic, no, that’s not the concern.
Ok…people on the non heritability of intelligence side(or whatever this debate is, I’m not sure. Basically the people who don’t agree with CP and Chen) - how do you explain those graphs?
http://www.timwise.org/2002/08/failing-the-test-of-fairness-institutional-racism-and-the-sat/
There is that, but other reasons are likely too:
It’s seen as a complex phenotype in neuroscience. See for example The neuroscience of human intelligence differences Nature Reviews Neuroscience 11, 201-211 (March 2010) or Neurobiology of intelligence: science and ethicsNature Reviews Neuroscience 5, 471-482 (June 2004).
In any case, quibling over whether its a phenotype or otherwise, it’s a measurable trait. Pinker comments:
The question here (as I understand the OP) is why do populations differ on average? Is it genetically plausible?
I was really surprised that there could be cultural bias in questions. Apparently they’re talking about the verbal section. Does anyone know if there are figures for the quantitative section alone? That should eliminate the bias.
That’s not a convincing explanation if you’re talking about well off families with higher levels of parental education for one group, and poorer families with less educated parents in the other.
That’s not true even by your own cite. There’s a big difference between doing a weak job of taking care of yourself and “perishing”
Again, that’s contradicted by your own cite.
That’s not true either. Let me ask you this: How many cases does your typical caseworker work on? Would you be surprised to learn that it’s a lot more than 1?
Besides which “enormous drain on already-strained resources” does not necessarily equal “non-functional” It might simply mean “piss poor.”
Even assuming a mildly retarded person would not follow simple instructions at all, you are ignoring the fact that a country with average IQ below 75 would have lots and lots of people available to plant and harvest crops.
Besides which, people with mild mental retardation are in fact capable of low level work in agriculture just as they are capable They may not be so great at it, but with guidance they can do it.
Again you are contradicting your own cite which implies that mentally retarded people in general can become fairly self-sufficient.
I don’t know. Keep in mind that you are the one claiming that African countries couldn’t possibly have very low average IQs, just based on simple observation.
Absolutely, although I would expect things would not run nearly as well as they do in the West. What’s your experience with people with very low IQs?
Ok, then please show me your proof that the average IQ in Africa is the same as it is everywhere else.
Also, do you agree that even in a country with average IQ under 75, there would be plenty of people available for agriculture, even assuming that an IQ greater than 75 is a requirement to participate?
Also, do you agree that in the United States, it is common for people with mild mental retardation to hold down jobs? And that such people generally do not have a full time adult supporting them?
I’m not sure what this means, but anyway, my point has been that one cannot, on the basis of simple observation, reject the claim that African countries have very low average IQs.
And we’re countering with the point that your are wrong on every conceivable level. All you need to do is spend time groups that have very low average IQ and you’ll know that you are wrong. Or spend time in African nations. Or apply logic and reason.
So you contend that one would not notice that half of one’s peers were functionally retarded?
The line from the cite was: “Approximately 85% of the mentally retarded population is in the mildly retarded category. Their IQ score ranges from 50-75, and they can often acquire academic skills up to the 6th grade level. They can become fairly self-sufficient and in some cases live independently, with community and social support.”
The cite does not address the question of what would become of such people without that care and support.
First: I’m addressing a claim of an average IQ of 70, you refer to “very low average IQ”. Do you mean 70, or some other figure?
Clearly, we disagree on whether a society where the average IQ was 70 would be functional or not. As far as I know, no one has conducted a study in which a population with that average was assembled and left to fend for itself. Based on my reading, and my (limited) experience with the mentally retarded, it seems clear to me that such a society would not be functional. You disagree. And so it stands, we cannot agree on “functionality” as a metric.
With no clear way to settle that question, I’m moving on to another way the issue could be settled: would such a society have observable characteristics that would betray the fact of an average IQ of 70?
You’ve mentioned a few observations: widespread illiteracy, nations that are dysfunctional compared to the West, being “piss poor” and so forth.
Based on the citations provided, it seems clear that such a society would, in fact, have distinctive characteristics. IQ is normally distributed, so an average IQ of 70 would result in large numbers of retarded people: 15%, that is every sixth or seventh person, would have an IQ of 55, and thus moderate retardation, for instance. To accomodate these massive numbers of mentally disabled people, African society would have to adopt a particular structure, in which the non-disabled adults supervise and care for the disabled ones for their entire lives. Or, some sort of formal or informal caseworker system. This would be observable, if it were the case.
Or, one could examine the local schools, in areas that had them. If every sixth or seventh child was physically unable to learn past the third-grade level, that would be evidence of an average IQ of 70.
Or, one could simply interact with a broad cross-section of African society. People who are retarded are distinguishable from those who are not, and an average IQ of 70 means fully half of the society would be noticeably retarded. People who’ve commented on their experience with Africans in this thread have not reported that experience.
Nothing extensive, a friend of mine worked at a local group home for a few years, and I interacted with some of the residents, plus the odd encounter here or there. I’m not claiming any sort of expertise, just relying on my reading.
Strawman; I never said that. I said that, through observation, it could be determined that the average IQ was higher than 70.
By way of analogy: If I objected to a claim that the average height in Africa was 9’ 6", it doesn’t follow that the average height in Africa is identical to the average height elsewhere.
If an IQ higher than 70 is required, then half the labor force is unsuited to work purely on that basis. That is a rather serious problem for a nation to have.
I’ve no idea how common it is. Do you? It’s certainly not common for them to live independently, that is, without an adult supporting them.
And, as pointed out, those polled were not experts in genetics or environmental sociology.
And there’s not more to cultural or environmental gaps than income and parental education? Really? Especially when talking about black culture?
Yes. But given how races actually work from a genetic standpoint, blaming genetics on the academic failure of african-americans is completely ludicrous. Given the insane genetic variability, to the point where many “black” haplotypes are further away from each other than from whites, trying to invoke genetics makes no sense. Especially when you not only have no genetic basis, and we’re talking about a group of people who were up until at most 2-3 generations ago legally and systematically disenfranchised.
Which is nice, but completely fails when used in conjunction with data talking about “african americans”, because as previously stated, the way we typically look at race is completely wrong.
I’m not sure you’ve really looked through this and other threads, have you?
To summarize race, first: It’s not a question of a quanitity of genetic variability that divides SIRE groups. It’s a question of whether or not gene variability which arose in groups isolated from one another passes equally to all groups. A gene variant which arose post the M/N split in out-of-africa populations would not be as penetrated among african populations as non-african ones, creating a predicted, observed, and functionally significant difference based on the frequency of that gene. See, for example, the X/X variant of ACTN3 discussion above.
To summarize the problem of explaining why high-income, highly educated black families have children who underscore low-income, poorly educated white and asian children: Which “cultural” (nurturing ) explanation would you like to advance? Actually, I’d be tickled if naive posters would simply stop advancing the SocioEconomic Status explanation, which has long since been soundly discredited. Whichever nurturing explanation you choose, why would it be a special case for blacks? Other SIRE groups (recent Vietnamese immigrants, e.g.) do not show a persistent disparity so stubbornly resistant to even the success of one’s own parents.
To summarize the genetic basis: Every gene is subject to random mutation, even ones which affect neurophysiology. SIRE groups have genes which are cluster by those SIRE groups, and that clustering is consistent with–indeed, highly indiciative of–positive selection. Would it not be more reasonable to suppose that genes have driven neurophysiological differences along with every other characteristic than it is to suppose nature has left off tinkering with neurophysiological genes since she perfected them 200kya with the advent of anatomically modern humans? Why is a genetic hypothesis for differences subjected to “find me the gene or quit talking” when we can reasonably normalize for nurturing variables the way we do for every other animal group and every other characteristic? We don’t demand “find me the gene for tallness.” We normalize nurturing and consider the residual difference genetic.
It’s only the deep fear that mother nature actually has built a whole raft of populations with disparate gene pools that drives this ridiculous constraint to solve for every conceivable nurturing variable.
But hey, if you think nurturing is the reason for observed differences, I would appreciate hearing your top one or two contenders, now that (in the specific case for the skillset of SAT-taking) SES is off the table, as is parental education.
And if I’m Harvard Med School deciding whom to admit, I have to struggle with whether or not to give a special placement to a black kid with crappy MCATS even though his parents are highly educated and relatively wealthy, and even though his college was the same as everyone else’s (and he still hasn’t mastered the material to anywhere near the degree of the white and asian subgroups).
This is the practical dilemma of the real world of mother nature meeting the egaliarians proud of their egalitarianism but having no actual explanations that hold up to scrutiny. If I just accept that we need a broadly representative society and that mother nature has not wired all groups equally, I can make a special preference for groups into which we culturally self-align. (And FWIW, this is exactly what medical schools, law schools, and most colleges already do–at least until Fisher wins her case with SCOTUS.)
I’ll advance the same ones I have before (I think I got them from Ron Unz)- lowered teacher expectations, peer group pressure, and lower academic self-esteem due to, among other things, media depictions. It’s nigh-impossible to correct for those – we’d probably need a biosphere to do it.
You can remain convinced that certain groups are genetically intellectually inferior (conveniently, I bet you are not a member of one of these groups you consider inferior), but there’s no reason to be even close to convinced. “Nurture” has not come close to being eliminated.
Here’s an excellent example of why you are wrong: Irish IQ, on average, in 1972 was 87. Now it is around 100. There was a big change, in just a few decades. It’s reasonable to assume it was not genetic. Knowing this, why must we assume that other groups with lower test scores have a genetic disadvantage? There’s no reason that some of these other groups, especially those with a very recent history of violent oppression, might not still bear some collective scars.