xenog123

Not really sure what your point is - when you mentioned the San people initially I thought you were trying to argue that IQ is not the prime determining factor of survivability, but now it seems like you're trying to make the argument that abstract reasoning or general intelligence has been selected for only so recently that there hasn't been enough time for it to be encoded into genetic differences. What kind of timeline are you looking at there? I'd guess something like g has been selectable since as early as agrarian societies and the existence of spoken language and alphabets.

So if you admit at least some genetic component to IQ, do you think that just determines baseline cognitive ability, and that through education/plasticity and equalizing environmental conditions everyone can in principle reach the same upper limit on human intelligence? I suppose that's possible, but consider the analogy to other physical traits/organs/system. Take something like muscle strength, for example. There are both genetic and environmental components to an individual's muscle power - proper nutrition and exercise can improve muscle development, and muscles can be said to be plastic in a sense. Yet clearly there is still an upper limit determined by one's genes - not everybody has the innate capacity to become a power-lifter, for example. The same could be said for other traits, like height, running speed, etc. So it seems like a pretty extreme case of exceptionalism to think that the brain, also a physical organ no more distinct from others, should be otherwise. It's not impossible of course, but... It's true that IQ tests were not initially intended as measures of general cognitive ability, but they were pretty quickly adapted to that use, and it has been the consensus for quite a while that g is a highly useful/meaningful factor, whatever it actually is. If you're going to reject that by the same standards you might as well throw out all social sciences. As for the idea of g being artificial or representing abstract abilities that don't correlate with practicality/survival, I think the fact that it is a good determiner of most mental functioning and correlates pretty highly with success in complex modern societies seems to imply it's not just some arcane construct only useful for book-learning. The counter examples you cited are kind of exceptional cases (the autistic savant types with high measured IQ but low practical sense or survivability, clearly a unique/deficient kind of phenotype) or the bush-folk that can survive in harsh environments despite their low IQ (again, a sponge with no brain can survive in places humans can't) that seem beside the point. Yeah that's a good point - why harp on about this at all. Like if this was your water cooler talk it'd be weird -"Oh hey Jamal, nice to see you. Hey, did you know that people of your ethnic background are statistically far less likely to pass a first year Calculus course? Well, see you at lunch." Anyways I gave my reasons for why its important in one of my earlier responses.

Man really.

Okay man I think I'm done splitting hairs with you - your analysis still has errors but we've strayed pretty far from the original point and I don't think it's worth wasting more time on this. You've also been insulting. Good day.

Well, a couple things. The estimate of 70 to 90 was from a cursory search. 70 to me seems pretty low, I would guess the average is actually higher. So if you're taking the absolute lowest estimate the yes it might seem unrealistic. Your math on the mean IQ of the migrant population doesn't make sense. You seem to think that a sample population with a mean IQ of 115 would have to be drawn from the proportion of the larger population that is above an IQ of 115, but that doesn't follow. If you're drawing a random sample from all those above 115 the mean of that sample will be > 115. I wouldn't assume that IQ and SES correlate that tightly - there could be plenty of bright Nigerians from less affluent backgrounds. I'm not sure about your stats on the size of the Nigerian American population - if the total population at a given date was some value, then it doesn't imply that that exact value immigrated all in that year. Presumably there would already have been some established migrants. I think those qualifying characteristics you mentioned would filter out more than 10%. An IQ of 85 is already pretty low and that's the 15th percentile, I'd imagine most migrants would probably be at least average. Well I don't know what anyone else has said about Appalachians but I would think genetics is a large factor in their low IQ - that particular sub-population was probably drawn from the lower proportion of the Scots-Irish distribution and has also been inbreeding for a while. It also wouldn't really be hypocritical to deny a genetic component anyways, since their environment is clearly impoverished.

I don't care too much about your insults but what irks you about the username? It's just a random pseudonym.

That study is interesting - if I've understood it correctly they linked educational attainment to particular genes in a sample of genomes of Black and White populations, estimated the degree to which those genes had been influenced by selection effects, and then calculated the expected differential in mean IQ between the populations based on some kind of simulation that made use of this information. They found the expected difference to be less than that of what hereditarians have claimed, and concluded that that position is not well supported. That's pretty cool and if the methodology is sound it's a useful advance, but I don't think it conclusively disproves the hereditarian (or at least "soft hereditarian") position. Educational attainment is just one imperfect metric, and there is a lot of room for error to leak in with the methods they used. I'll have to dig up one of the twin studies I'm talking about later. The reasons I cling to hereditarian ideas are the following: Your mind is your brain. Your brain is a part of your body. I don't see how you can deny that it is subject to genetic influence. Assuming IQ is a valid measure of some property of the mind (brain), the historically measured gaps in IQ (and their measurement is basically factual) have persisted for so long and across so much societal change it seems difficult to imagine how they could be purely environmental in origin. Even just looking at score results from say the early 20th century to the 1980s (before the more recent data) the gap remained fairly constant even with the Flynn effect. If this was the result of improvements to environmental conditions, it seems unlikely that both populations would experience nearly identical rates of improvement if the sole cause of the disparity to begin with was environmental factors.

Well regarding the nature vs. nurture debate it seems kind of obvious it's a combination of both. I would think genes set the upper limit on IQ and then environmental factors determine the rest. Twin and adoption studied are pretty telling - from what I recall reading if you take, say identical twins from a lower SES and place one with an upper middle-class family and one with a family of low SES, the one raised in the richer environment will end up with a higher IQ than his twin, but still lower than that of his adopted family. If environment was purely the determining factor you'd think his IQ would rise to exactly that of the adoptees. As for what IQ measures the whole point is that it's supposed to be general intelligence, since most cognitive abilities are found to strongly inter-correlate (see culture-fair tests). For the example of the survivalist bushman with the 70 measured IQ, that sounds like saying that like, a sea sponge with no brain rivals a human's intelligence because it can survive on the ocean floor where a human being would just drown.

Well the logic is basically something like this - assume you have two groups of identical IQ distributions. If you're selecting some subset of one to move to the other based on even rudimentary selection criteria (high school education, some work experience, no criminal record, knowledge of opportunities in other countries) you're implicitly filtering out people below some IQ threshold, and so the minority population in the new country will have a higher average IQ than the natives. That's interesting to hear about new research in the field. I didn't get the impression when reading Jensen that he was actually manipulating data. In terms of "grand narrative" fallacy it seems there might be the opposite trend now towards an egalitarian spin that sees everything as socially constructed. Those SNP studies are really not conclusive in my view, since we still have such a poor understanding of which genes are linked with measured intelligence. And I just can't fathom anyone who would do away with any hereditarian ideas entirely. Look at something like twin studies, for example. Or even the idea that you could have identical twins whose every physical trait is identical (clearly because of their shared genes) but their brains are somehow immune to this.

Uh okay man

Those kinds of programs aren't the ones I'm talking about - I'm referring to things like affirmative action. If you look at university admissions in the States, for example, you'll find that in an effort to yield a "fair" distribution ethnic groups that are more objectively qualified as measured by metrics such as GPA and exam results are discriminated against in favour of those with inferior qualifications (Chinese-American males are actually the most severely discriminated against in this regard). So in this case the idea of meritocracy is being jettisoned in favor of equity or whatever, obviously not an ideal policy.

Why are you even assuming I'm white? And yes it's pointlessly rude.

Who are you addressing here exactly? That's kind of out of line whoever the target may be. And it doesn't even really make sense to refer to a White person as "bleached" if they were born that way, if that's what you meant. Yeah that was just the first study a search turned up. I haven't read Rushton's work directly but am familiar with Jensen's. As for the gap narrowing there is some evidence it might have narrowed a bit, perhaps from 1 to roughly 0.7 standard deviations below the mean, but the most recent studies that I looked at are still kind of mixed. Even if it's narrowed that much due to an improvement in the (presumably) asymmetrical life conditions that caused the disparity in the first place it still seems like a pretty massive gap. And I kind of wonder at just how much you have to equalize environmental factors anyways - does education actually improve fluid intelligence (one would think not by definition), or is it enough that one has adequate nutrition and other material necessities? I would agree that the hard delineation idea is simplistic though. Does the 1000 genome study you mention refer to genetic links between races and IQ or just genes and IQ in general?

The ethnic factor there could still be explained by immigrant selection. The gender trend is quite clear though. As far as I know recent IQ testing hasn't shown a growing disparity between males and females, so my first thought would be to ascribe that to just differences in work ethic or enthusiasm moreso than pure cognitive ability. I think historically males and females had similar mean scores on formal tests line this so that's a remarkable divergence, especially if IQ hasn't changed. But I'd have to do more research. Anyways I've got to take a break from this for a bit.

I mean it says right in that article that applicants have to meet some requirements for education, job training and work experience. There's also the self-selection factor, in that those who choose to apply are more ambitious, driven, higher IQ. Yeah clearly environmental factors are huge as well, I'm not denying that. The only reasons one should care about heredity or group differences are, imo: Zeal for scientific truth To inform better policy making In the West the assumption that race or gender based disparities are mostly or entirely due to discrimination has informed a lot of social justice-style corrective policy that is probably just totally wrong-headed or impractical.