OK, but it sounds like you’re agreeing that if the populations were separate - to some degree - for long enough time, then it would be expected that they would eventually come to vary even for complex functions like intelligence.
So the question is whether the amount of time that these population have been separate is in fact enough for that. I have no idea. Do you?
I’m pretty sure there has not been significant separation at all- there has been interaction and certainly gene flow between Europe, Asia, and Africa pretty much continuously for the last 50 thousand years or more. This is evident by any trips by land… if you go from village to village, starting at any point in Europe or Asia or Africa and going around the coast, you will write down in your journal “the people in this village look pretty much the same as the people in the last village” at every stop, even if you start in Korea and make your way around China, SE Asia, India, the Mideast, and into Africa (and around to Europe). Before the age of exploration, there was separation of a few thousand years between the Old World (Europe, Asia, Africa) the Americas, and Australia (and surrounding islands).
Truly separated groups, like the different subspecies of Gorilla, for example, have far more disparate gene pools than any two groups of humans.
F-P: My understanding is that we currently think intelligence evolved largely because it helps us form larger social groups. I have no idea if there is selection pressure on the aspects of intelligence measured in SATs, as distinct from the aspects related to remembering which baboon likes it nits to be picked in clockwise fashion or using language. I was only positing that there would be more or less uniform selection pressure, unlike many of the known differences between population groups having to do with their particular environments.
So I don’t know that we would expect selection to act upon mutations relevant to intelligence. But assuming it is a trait (or related set of traits) that is under selection pressure, I think it’s a question of (a) time; (b) degree of separation of the populations; and © average time it takes for a beneficial mutation for a complex trait like this.
I don’t know much about (b) or ©, but I think there are people who do. That’s who I was hoping to hear from.
I’m not all that familiar with these facts and am not sure the same time period you’re talking about is the proper one.
But regardless, one important thing to bear in mind is that, as compared to differentiation between species, or even subspecies, we are discussing really really small differences. These are magnified in our minds because in modern society and among people even tiny differences are relevant to us. I don’t think we would even be discussing differences of this magnitude if they were between different populations of animals.
So the fact that different populations of people have not been as isolated from each other as different subspecies of animals are is not meaningful.
Worth noting that there is also a cost of intelligence as well, and if this cost is something that has disparate selection pressures then that would also result in a variations in average intelligence, even if the advantage of intelligence itself does not vary.
Meaning, suppose in order to achieve greater intelligence you need to sacrifice Trait X, and the sacrifice of Trait X has a bigger impact in one environment than in another, then that would itself impact the selection for intelligence.
But in any event, the point I was making was that even absent any disparate selection factors, there would still be some expected variation over time. You’ve not addressed this explicitly, but I’m assuming you agree with this.
That’s fine, but until that point your “amateur intuition” would seem to have no basis at all.
Okay, sure–the degree of certainty differs between “we know why African American kids tend to score lower on standardized tests” and “we know why helium balloons float.” I don’t see that, as you do, as a fatal flaw in the analogy, because science is always about degrees of certainty. The best explanation we have for differences in socially-constructed groups such as racial groups is the effects of social structures. Those structures appear to explain what we see adequately.
But yes, because we don’t have a control group for society, nor are social experiments easy, ethical, or even feasible most of the time, our outcomes are necessarily a little bit less sure. That doesn’t change the basic idea that we already have a very strong candidate for the difference between these groups, and self-respecting scientists won’t keep trying to find ways to prove disproven theories using new mechanics.
I think that’s more or less right, though I think selection pressure is probably related to how much time is necessary for a trait to become widespread in a population.
I think you’re overstating here, but I agree I’m just speculating with a high school biology level knowledge of these matters. But my point is that it’s not obvious from the mere fact of separate population groups that we would expect those groups to evolve different intelligence-related genes. That’s wildly simplistic, and ignores even the most basic variables of time, degree of separation, and complexity of the trait. So I’m unpersuaded that I should infer anything about genetic differences until I hear more about those factors, especially when what I know about the time periods and degree of separation in question suggests that we would expect most differences to involve a single gene or a small number of genes.
”The best explanation” implies that there needs to be one explanation, which is not correct. There could be more than one factor.
I would almost agree with this, with a crucial difference.
I would put it as “based on what we know, those factors cannot be ruled out as causing the entire discrepancy”. You seem to be saying “based on what we know, those factors are able to explain the entire discrepancy”. These are different, and I don’t think the latter version is correct.
I think everyone agrees to that. The point I was making – actually, Chief Pedant was, IIRC - was that two populations facing identical selection pressures would still be expected to grow genetically apart, given enough time, due to the random nature of mutations.
Right. And since time, degree of separation, and complexity of trait are crucial factors here, until we know something about that we know nothing. Because given enough time and degree of separation there would be expected to be differences. So absent that we really have nothing to go on.
I agree with this – we can’t infer anything at all until and unless we know more about these factors.
But my point addressed to iiandyii above bears repeating. We are talking about very small differences here. Even at the completely unreasonable extreme, if we attributed the entire current measured differences in intelligence to genetic factors and none at all environmental factors, it would still be a very very small difference with enormous overlap. It’s not remotely comparable to differences in color, hair texture, and the like, which have a much much greater degree of differentiation.
So when saying that these latter attributes are much simpler and require much fewer genetic changes than intelligence, it’s important to bear in mind that we are also correspondingly discussing a much smaller degree of differentiation in the case of intelligence.
“Explanation” is an umbrella word: in post 163 I used the phrase “a wealth of factors” to talk about what caused the discrepancy. I’m using “explanation” as a single word to encapsulate all those factors. I agree that it’s possible in theory to have some sociological factors and some genetic factors, if that’s what you’re saying, but I think the “wealth of factors” that are sociological suffice.
Why do you think the former is correct and the latter is incorrect?
Again, it’s extremely difficult to “prove” anything sociological with the degree of confidence that we “prove” physics theories, due to the difficulty of obtaining a control society. But when we’re looking at decades of Jim Crow and slavery beforehand and continued institutional and individual racism afterward, we’ve got causes more than adequate to explain the effects we see–especially when we look at cases such as African American children of professors, first-generation immigrants from Africa, IQ scores of modern African American children compared to scores of white children of the 1950s, etc.
We’d expect them to grow apart in a few ways:
I don’t see that any of these cases apply to intelligence. Number four miiiiight apply, but the way to find that would be to find that mutation.
The “more than adequate” part is what we don’t know.
We know generalities. We know that A) environmental conditions influence intelligence, and we know that B) the type of environmental conditions that black people in this country have been and are subjected to negatively impact intelligence. That’s what we know. What we don’t know is whether C) the degree to which the type of environmental conditions that black people in this country have been and are subjected to (to the extent that it’s even possible to quantify this) could account for the scale of the measured difference.
We can speculate based on A & B that it’s possible that C is true, but we can’t say that we know that C is true. If you have any knowledge of C, as opposed to A & B, I’d be interested in the source of this knowledge.
I thought all mutations are once-off or vanishingly rare. So the notion that it might happen in one population and not the other seems SOP to me.
Finding that mutation would be enlightening, but that doesn’t mean that in the absence of this knowledge that possibility should not be considered.
I think you and I both agree that it would be “good” (in some vaguely abstract sense) if we could demonstrate that all differences in black-vs-white-test-taking were due to environmental and social factors, right? Therefore, it would be nice if there were a study that might conclusively prove that. However, any self-respecting scientist who set out to come up with a study which might conclusively prove that would have to recognize that for that study to have any meaning whatsoever, it would also have the potential to end up with a conclusion that they didn’t like.
Should no such studies be done? For that matter, other scientists might be doing studies about genetic basis of intelligence with absolutely no thought to racism-y implications whatsoever but just for the pure knowledge of knowing what intelligence is, how genes work, etc, etc. But one might imagine some theory proven by that scientist being (mis)used by racists to support their agenda. Should that scientist be afraid to do that research?
Tangential hypothetical: Super-intelligent aliens make contact with us, start teaching us all sorts of neat things like FTL travel, anti-gravity, etc. Then they say “oh, by the way, we noticed that you have a really serious ongoing controversy about what you refer to as races and intelligence. Well, we used our full-planet-molecular-level-super-scanner to conclusively determine the genetic intelligence potential of every human on the planet, and then grouped those by what you would view as races, and also used our knowledge of your DNA to calculate exactly how much of that is or is not hereditary. We are entirely confident, with our millions of years of knowledge and experience, that our analysis is comprehensive and correct. We’ve put the results in a sealed envelope, here it is”. What would you do with that envelope?
Honestly, I’m astonished that you’ve read my posts and have any doubt what I’d do with that envelope (edit: or about whether scientists should do research).
From the first page:
and:
From the second page:
and:
From the third page:
and:
From the fourth page:
Are you seriously in doubt about my position regarding alien technology?
But it’s not different, and that’s the whole point. We don’t have any trouble at all saying that dolphin brains or chimp brains work differently from humans because of genes. We don’t even have any trouble assigning differences within non-human animal species sub-populations a difference based on genes.
The only reason you want any non-superficial question to be “different” is because for you, assigning a difference to genes is distasteful. It’s “racist,” even. If it’s a characteristic that you–entirely arbitrarily, from nature’s perspective–assign to a superficial characteristic bucket, you don’t care if genes drive the difference. You’re pretty happy to accept that genes and not nurturing drive a difference in physical appearance, even though you have not identified those genes nor have you ruled out absolutely the influence of every possible nurturing variable. It’s just a persistent pattern, and hey; it’s for a superficial characteristic.
However, if the characteristic in question is suddenly not superficial, you want it to be treated differently. But nature isn’t like that. She is just as likely to tinker with some sort of gene that creates a bigger hippocampus, or faster muscles, or denser bones or different torso/leg ratios or…well, you get the idea.
It is probably laudable that your personal standard is that, without the exact gene or without a large-scale study for every variable, you aren’t going to buy a “racist” gene-based proposition. I get that. Good on you. But it’s not science you are arguing for. It’s faith. It is highly implausible that nature has tinkered only with genes that drive only superficial changes.
(On the Jamaican comment I made…
If we find a one population who outperforms a different population from the same SIRE group ((but has a reason for a historic split of some kind)), that’s an argument for genes; not nurture. Only a very confused thinker would assume every black subpopulation performs identically. Any SIRE group can be extensively divided. If black offspring of Jamaican immigrants outperform their black peers here in the US, it should give you pause for a nurturing argument about teacher expectation or stereotype threat or whatever. It’s more likely their average gene pool is different since they will be perceived to be the same SIRE group. Perhaps only the brightest subgroup has the opportunity to emigrate; perhaps the admixture of source genes is different…whatever. But a lot of putative nurturing variables go out the window when a sub population of a SIRE group kicks ass in the same nurturing environment that is supposed to be holding that SIRE group down. It’s not that hard to define subpopulations of blacks who are substantially higher-performing academically than some subpopulations of whites, and dollars to donuts the reason is better intellect genes for that black subgroup.)
Sure, inasmuch as they’re, yanno, different species. I realize you don’t mean to suggest that humans have subspecies, but I think you’re onto a flawed parallel there.
It’s different because of the consequences. Standards are not so high for claims that don’t potentially have devastating consequences; if Sri Lankans are slightly more likely to get chronic condition X, according to some research, then it’s not a big deal to go ahead and say it. They might be wrong, of course, but it’s just not that important if they happened to be wrong. Racist claims are different. The standard is higher, and it should be higher, and the “blacks are dumber” crowd is not even close on the data and evidence.
It’s not a question of wanting. It is different, as we can all see with these discussions, and by looking at history.
It already is treated differently, as it should be. There’s no question of “want”.
And for such claims, especially about the brain, there better be extra-strong evidence. You’re not even close.
Yes, good on me for demanding strong evidence for such a claim. Even without treating racist claims differently, the genetic hypothesis is incredibly weak. It doesn’t fit all the facts, as Frank Sweet has pointed out. It doesn’t mean it’s false, but there’s no good reason to accept it at this point.
Basically, your argument is “genes can vary in different groups, therefore they are different for intelligence in different groups, therefore they explain disparate outcomes”. That’s weak. In this world, unequal as it is, disparate outcomes can’t tell us anything about genetics. And since we can discount the outcomes, because they can’t possibly tell us anything about genes among such obviously (and hard to quantify) disparate opportunities, then picking one group as more or less inherently intelligent on average is a crapshoot. Any group could be at the bottom, and any group at the top.
Whether it’s plausible or not, this tells us nothing about any group being inherently more or less intelligent, on average. You think the disparate outcomes tell us which groups are on top and bottom, but that’s weak. The only bar you’ve reached is, at best, the “perhaps there’s a non-zero chance that some groups have a greater likelihood towards having the genes for high intelligence”. That’s it.
Why is this more likely? It seems just as likely that non-genetic factors could be at play- parenting skills, local teacher expectations, overall media environment, peer pressure, etc. For the genetic hypothesis to be supported by this, it seems that you’d have to prove that the Jamaican gene pool is different than all other groups of sub-Saharan African descent- which seems highly unlikely (why would Jamaicans, who descended mostly from West Africans, have a substantially different gene pool than Haitians, or Cayman Islanders, or black Cubans, etc?).
This is an excellent example of a “God of the gaps” argument. Okay, you say, so you think that sociological factors explain everything? Well, look at this one instance that appears to contradict the major sociological factors you’ve mentioned. Can’t explain it instantly? GENESDIDIT!
No. If we can’t explain it, “genes” aren’t the default explanation, since we haven’t seen them explain anything similar to this case. The default is that differences in socially-constructed groups are explained by social differences, since that’s the explanation that over and over has borne fruit.
I wasn’t clear, and I apologize.
Within the overall group of domestic dogs, we don’t have any problem taking out subpopulations that we have selectively bred and assigning to them different characteristics that we agree are genetically driven.
We don’t have any struggle worrying that the intellect of a border collie may be different from that of an italian greyhound, or that their physical skills might be different, and that those differences might be underpinned by genes. In fact, we assume they are underpinned by genes because we have artificially manipulated nature to select for specific gene-based variations. And of course nature does this herself, over time, which is why clinal variations eventually produce quite different average gene pools once two clades are widely enough separated.
The point I am trying (poorly) to make, is that we do not demand a geneset with identified functions to decide there is “genetic evidence” for a difference, with a single exeption: We (at least iiandyiiii demands that if the functional difference is non-superficial, and the species in question is human. I really object to iiandyiiii’s repeated use of the phrase, “no genetic evidence” when what he should be saying is “no genetic proof.” The only reason he applies that standard to humans is that he thinks saying otherwise is racist. It isn’t because he’d apply that standard to any other characteristic, or any other species under investigation.
(bolding and underlining by CP to call out the sentence)
No. Basically my argument is that gene pools DO vary, and there’s no scientific dispute about that. Various skillsets vary, and consistently so across a broad range of nurturing, cultural background, and political system. It is a highly persistent pattern and surprisingly predictive. In the case of the US, it’s a pattern stubbornly resistant to efforts to alter it; so stubborn that even reversing long-assumed nurturing advantages such as socioeconomic status still do not erase the pattern. Since gene pool variance drives other characteristics, it’s plausible that gene pool variance contributes to these stubbornly persistent patterns.
I appreciate your sense of history, but I am unpersuaded why something that happened to my grandparents should affect my ability to perform an exam, particularly if my own parents are themselves quite privileged and educated. I understand your mileage varies, but you not only have to throw out some very weak and inconsistent variables which are different across every political boundary (there’s no slavery history in Sweden, e.g.); you have to make a faith-based assumption that nature does not mess with human genes–and only human genes, b/c you would not make this argument for neurophysiologic skillset differences in clades within other species–which code for significant differences.
You are forced to arbitrarily set off significant differences as not likely to have been touched by nature while simultaneously admitting that genes which drive other differences have been tinkered with. Worse, your reasoning for nature to have been unlikely to have tinkered with significant genes has nothing to do with science. Your reasoning is that such tinkering would result in “racist” conclusions being correct. And you don’t want that, so you set a completely different standard.
That’s fine, but it’s arbitrary, and it’s completely unsupported. Nature doesn’t give a crap if she is giving one group an advantage. She toys mindlessly with every gene in a completely random fashion, and should one descendant group end up having a different skillset, not only does she not care; she doesn’t even know. Because nature does not do Intelligent Design, and she doesn’t create. Those anthropomorphic concepts have nothing to do with the way the world works. You are determined to press a cause for Fair Design where no Designer is arbitrating fairness.
I don’t want to sidetrack into a peripheral discussion about Caribbean admixtures, but basically there isn’t any data I’ve seen that suggests emigrants are a representative cross-section of their source country any more that country folk who emigrate to the city represent a cross section of the folks they leave behind…one can readily postulate that the best and the brightest of the source pool are at the top of the get-out-of-Dodge crowd.
Perhaps, then, you should develop your own sense of history. This is a hugely naive view of human society, individualist to the point of self-parody.
…and tremendously difficult to grok.
While I agree with you in sentiment, I’d suggest cutting the guy some slack. It’s a damned tough subject to get one’s head around.
Your failure to be persuaded is unpersuasive. 
You keep looking at socio-economic status, (basically, current wealth), and declaring that the people affected have the same culture. (Your own variation of egalitarianism.) However, there are multiple routes to wealth, (particularly in the U.S.), and the approaches to reading, to raising children, and a host of other factors affect the learning skills of the children of any group. Simply declaring that everyone at the same income level has the same opportunities and culture is to ignore reality in a significant way.
Picking two groups who are often cited for superior intelligence, Jews and East Asians, one can find all sorts of information regarding the way that education and success are held up as family goals that are passed down from generation to generation. Other groups whose priorities in raising children place less stress on those particular goals, (having no similar cultural tradition), would seem to be less likely to pass on those traits to their own children, regardless of their current wealth.