You’ve allowed elsewhere that it MAY be the case that the races differ in average intelligence. If they found an intelligence gene tomorrow and this turns out to be the case, will you be “offended” by nature, genetics and evolutionary forces?
If I may digress, out of general interest, some of the “empty” gene locations do suggest that the initial hybridizations were difficult and had a fitness cost. I.e. few matings actually resulted in a child, and few of those children managed to pass their genes on.
Also, the hints of a general north-south cline in the retention of Neanderthal genes, from Europe to east Asia, and the much higher percentage of Neanderthal genes in the older European population represented by Otzi the Iceman, does lead to interesting speculations about the adaptive value of the neanderthal genes.
I am unsure, but leaning towards no.
What you are talking about is basically the root of an allopatric speciation process. Which generally requires entirely separate gene pools. But even assuming that there have been very little genetic exchange between sub-saharan and other population groups, we have an exchange in the US. If we have two populations of the same size and totally mix them, individuals will contain an average of 50 % genes from each group. At the moment we have an 80-20 split. That is nearly halfway there.
I don’t know if there is any definition for how much mixing you can have in gene pools and still call them “separate”? But I suspect that halfway to fully mixed does not qualify.
Anyway, I am going to be away from the computer where Ive saved my long-forgotten password for this site for the weekend. But before I go I want to address a different point:
Don’t know how I would feel. I’ll cross that bridge on the off chance I come to it.
I’ll note that you could ask the same question to CP, since he finds the non-genetic explanation “insulting and demeaning” – if it was proven that history, culture, discrimination, etc., were the causes of the test-score gap, and the genes for intelligence were the same on average, would CP be “offended” by history, culture, discrimination, and the like?
In this debate, we are looking at whether the underachievement of black people have a genetic or non-genetic cause. And we’ve discussed difference in gene pools, average gene frequencies, etc.
However, as I remarked further up, genetics is not just genetics. It is entirely possible that there could be genetic mediation of the issue in question with no genetic difference in the gene pools whatsoever.
There is something called “epigenetics”. Briefly, environmental alteration, not to genetics but the expression of genetics. And this expression can be inheritable.
For example, after the “hunger winter” of starvation in the Netherlands in 1944-45, children who gestated during the famine ended up shorter than the average. As expected. However,* their* children also ended up shorter. But the children of those kids are among the tallest in the world. What we observed there was that the starvation process influenced the expression of genes, or some of the genes regulating height. And that it also influenced the genes influencing the expression of genes in the children of the affected. Basically, and alteration to the behavior of genes that took generations of ample food to reset.
It is entirely possible that some of the genes influencing intelligence are affected by similar processes. In which case we’d see a similar pattern of academic underachievement among other disadvantaged groups, which would vanish a few generations after the group-situation normalized.
Maybe not in this thread, but that point has been made in one of the several similar threads and largely dismissed by the “genetics explains it all” crowd.
The federal school lunch program by itself shows the simple act of feeding kids leads to a drastic improvement of test scores, but somehow this is apparently not evidence that we might not have normalized situations sufficiently for a direct comparison.
Honestly, I am not sure if an examination of the US situation is going to yield any answer, or much relevant information. The US has a strong racial divide, which historically has been even stronger.
It has a history where academic achievement for Blacks have been difficult at best, or even heavily discouraged. Sports have been the vehicle where black people could succeed and more recently the military.
And there is a culture where black people gets called an oreo if they do we academically, and get disrespected by their peers. Black people get bombarded from childhood with images of rappers going on about bitches and bling. Gangsta culture throws them starts and idols. (This is a peer-transmitted process by the way -independent of parental status. If underachievement is genetic, we’d expect it to be mitigated among the children of academic achievers, whereas if it is cultural, they are equally vulnerable.)
But the point is, both theories explain the observations we make. Hence, there is little to be gained from focusing on the US.
What would be a strong argument to me is if someone collated the academic results of infants adopted from the third world to western Europe, and compared the results of sub-Saharan adoptees with the Out-of-africa ones. If that showed an under achievement in the Sub Saharan group, you’d have a real argument for a genetic origin.
Which could still be epigenetic, of course.
Oh and just a quick thought: Ive previously asked why the US is the only place that such a signal shows up, or shows much more strongly that the other places that have had a west African population.
Is it possible that the strong suppression of blacks in US history combined with easily accessible education have resulted in a Darwinian pressure against academic inclination among US blacks?
This “crowd” (at least as far as you’re talking about a subset of the SDMB), as far as I can tell, has a population of exactly zero. Is there someone I’ve overlooked? Can you point to these posters? I don’t recall anyone being of the mind that culture/nurture cannot or do not play a role. The question is, “Can it all be explained by culture/nurture?”.
In my opinion, the three hundred year cycle of slavery in the American colonies and the U.S. is too short a time for such an effect to come into existence.
You’re probably familiar with the UL that the Napoleonic Wars led to the reduction of the average height of French men, because the tallest men were taken into combat regiments, which suffered huge casualty rates. But the truth is that fairly simple genetic statistics disprove this. The wars would have to have killed off some 95% or more of all men above average height – and before they had a chance to reproduce! Many soldiers went off to war, but left children behind them!
Similarly, in the old slave states, they would have had to have killed 95% or more of all slaves who were above average in intelligence, to make a significant reduction in average intelligence. Nothing even close to that happened; in fact, the reverse, as the smartest slaves often were given better jobs and more favorable treatment.
The time period is just too short for meaningful evolutionary pressure to lead to such a significant group differentiation event.
(This is also the rebuttal to Jimmy the Greek’s famous blunder, that black basketball players are big and strong because they’re descended from slaves, who had to be big and strong to survive. The difference in survival rates was simply not great enough to have made blacks that measurably different as a population.)
Didn’t look very hard, then.
For the first part: it’s in the OP itself. This very thread was started back in 2009 because both CP and brazil84 suggested that culture/nurture factors are sufficiently controlled for to determine that genetics explains academic performance differences in black students.
Also, that’s not what I said. I did NOT say these posters claimed those factors do not play a role but that they claimed those posters dismissed those factors as explanations. Like I said, it’s in the OP - “when one factors out poverty”.
That’s not really a subtle distinction. In fact, that’s rather a large mischaracterization of my post.
Anyway, here’s one post in another thread where CP directly claims that all non-genetic factors have now been normalized and that genetics is the explanation for performance differences:
(bolding mine)
But going to a different thread isn’t really necessary. CP makes the claim in this very thread in this post, for which this is a very relevant quote:
(bolding mine)
In other words, CP claims those factors are sufficiently controlled, which is and has been a major ongoing bone of contention in this thread and several similar threads before this one.
As for other posters, well, yes, others posters have made similar claims. The aforementioned brazil84, for one. I really don’t want to dig through several depressing threads on racism to find more of these examples, so I won’t. There’s plenty of them out there, if you want to find them.
Average.
It is a little tiresome to have to repeat every detail every time, but it case you truly are having difficulty grasping this…
The source ancestral populations for europeans and US blacks have been separated for more than 65,000 years; in the last few hundred admixture has occurred to an average of about 20% for one cohort; a few percent for the other.
This leaves two average gene pools.
If pictures help, think of two jars of 100 marbles; white and black. Take out 3 white marbles and put them in the black jar; 20 black marbles and put them in the white jar. Now draw from one jar or the other randomly and ask yourself which jar is more likely to give you a white or black marble.
That’s a simple picture of what happens with average frequencies for genes in your pool even when there is admixture.
Take your condescension to the Pit.
I wasn’t quibbling with the “average gene pools” sophistry, I was quibbling with the “separation”. 25% admixture means no real separation.
You’d see that if you were capable of seeing clines instead of clusters.
As a reminder, we have an average of 20% admixture for one cohort; a few percent for the other. We have nowhere near a fully homogenized set of cohorts.
WRT injecting an implication that some sort of speciation standard needs to be met to show any real divergence in gene pools: LOL.
Evolution almost always diverges separated groups; mother nature blindly creates a new menu of gene variants for every gene; reproductive success (in turn influenced by an assortment of external events and pressures) drives persistence of those variations.
Over the long haul, speciation, perhaps; over a shorter run, distinct differences in average penetration for any given variant. And even a single SNP variant may have profound implications without there being any significant movement toward speciation.
It’s very clever to try and wordsmith the question by coloring the debate with an implication that this is about speciation. I love that sort of rhetorical sidestep as an answer, but it’s completely irrelevant.
The source population(s) for–on average–80% of the genome of a self-identified US black is about 65,000 years removed from the genome of the source population(s) of a self-identified US white.
Here is a chart using mtDNA tracers; another for Y DNA tracers. Both show widely-accepted approximate migration patterns.
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The result of that human migration history, with the vicissitudes of evolution superimposed, create two average gene pools, with average frequency differences for thousands of variants (not to mention 1-4% introgression of a completely different archaic genome into one pool and not the other.
The functional effect of these differences is self-evident for the superficial appearance differences which trigger the self-identification in the first place; as mentioned above thousands upon thousands of medical studies show average physiologic differences for both disease and non-disease-related traits.
There is no requirement to meet a speciation definition of any kind to suggest that average gene pools are different for average frequency of genetic content.
But I completely understand your hesitation to bluntly admit that these two gene pools have different average frequencies for gene variants.
It’s too close for comfort to admitting that mother nature forgot to stay egalitarian across separated populations.
If we can’t even get around the wordsmithing and be able to bluntly state that these two cohorts represent source populations separated by 65,000 years, I don’t think you’ll need to find a computer with a password you know, because we’ll just keep talking past one another.
I’m pretty sure the scientific literature will continue to talk about sub-saharan and non-african gene pools, though. 
I find the Y and mt DNA patterns very interesting, but it’s strange when you cite something like “widely-accepted approximate migration patterns” when the two forms of DNA tracking don’t actually agree on the migration patterns.
I think this (and other data) goes to show that the actual history of human migration was extremely convoluted, with constant and repeated doubling-back and leaping forward.
Uggh. More egalitarian straw man nonsense. Why bother with this crap?
Laughably unlikely for children of highly privileged parents…but dream on that epigenetics will be the salvation of this gap instead of the far more obvious: these are two source populations separated, on average, by tens of thousands of years of evolution.
Still, an epigenetic explanation is a great straw at which to clutch for some.
I wonder if we’ll find the egpigentic drivers for why self-identified whites and asians can’t compete at basketball or sprinting?
I don’t mind being quoted, in context. I am not content with this summary of my position unless you add the qualifier of SES controls as well when comparing gaps.
To be clear, what I hold is that an average difference in gene pools is the most likely explanation for the academic performance gap which persists between self-identified blacks and self-identified whitesasians in the US when cohorts are compared where the black cohort has very high SES-based privilege and the white/asian cohort has low SES-based privilege.
I hold that opportunity for educational achievement parallels parental wealth and educational achievement (which in turn parallel social/class status).
Highly educated black parents are likely to value high educational achievement for their children. They are likely to have a conceptual grasp of how to navigate the educational system and what factors are involved in how to learn. They are likely to engender those values for their children. Yet their children, on average, score barely on par with whites and asians from families with very poorly educated parents.
Wealthy black parents are likely to value educational achievement for their children even if they themselves happen to be wealthy for non-educational reasons (business; entertainment; sports; whatever). I do not find persuasive an idea that a wealthy black parent just wants the kids to coast off the family dole, or has some sort of anti-educational bias, or cultural crippling that prevents them from thinking Jimmy should keep his ass in school and learn. Those wealthy parents have the resources to effect whatever opportunity needs to be effected…better schools; tutors; whatever. Yet their children score barely on par with whites and asians with very limited economic opportunity.
I hold that nuturing is an important variable, but I do not hold that black parents are somehow unable to grasp the value of scholastic performance, and I do not hold that black children are unable to prioritize it either.
Neither do I see any evidence that, at high SES tiers, there is some sort of black beat-down on the part of the educational system.
I am reluctant to use anecdotes in GD, but in my professional experience (I grant you; only for the very highest level of education–4-8 years post college in the sphere of medicine) there is no support for this idea of a cultural or nurturing beat-down directed against blacks. I do not see any evidence that college tiers are any different. Racism and anti-black sentiment exists at some level throughout society as do many other examples of tribalism, but the idea that it obstructs education is not tenable, in my opinion, and in fact that sort of tribalism is itself ostracized rather robustly when it is overtly expressed.
My personal experience closely parallels my professional one for shaping these sorts of anecdotal impressions against the idea of a general black-culture anti-educational bias, internal or external. Our closest friends are Nigerian immigrants; highly educated and professionally successful. Over Christmas dinner at our home we chatted up the kids yada yada yada, and the conversation was around general adjustment along with whether their two kids were the most popular in school with teachers and friends, or possibly only second. I have relatives who teach AP in high school; a huge part of their focus is getting their black students to achieve. When they get a black kid who stars, their joy is palpable.
In short, although there is no dearth of anti-black shitheads and clannish behavior, I see no evidence that it rises to a level which would account for a stubbornly persistent average gap in performance outcome for black children from wealthy and educated families. I have seen no persuasive nurturing variable which is so powerful and pervasive for blacks such that wealth and education at the parental level is unable to overcome it to such an extent that children from these families cannot compete on par with any cohort except the poorest and least educated white and asian ones, on average.
I recommend additional reading.
As a rule of thumb, mtDNA tracing reflects matrilineal migration while Y chromosome tracers track daddies. Moms tend to be a bit more mobile since pops hauls them off to the new digs more often than the other way around.
But if you are thinking those two patterns show a broad disagreement, perhaps you could study some general references instead of simplified charts.
There is broad agreement on general migration patterns; broad agreement on out of africa as a splitting point; broad agreement on the extent of “doubling back and leaping forward” (I think; depending on what you are implying there).
Think about using Neanderthal DNA as a post-out of africa marker, and go read about the extent to which that has penetrated sub-saharan v non-african groups, on average.
Average.
Then reconsider bristling when I suggest mother nature does not dole out gene variants into descendant lineages after an original coalescence point in some sort of egalitarian fashion: "One for you, and one for you, and one for you…"all from the same source pool.
Or the far more likely (in that it’s not refuted by specific experimental data) explanation that society still treats the two groups, regardless of wealth, in a profoundly unequal way.
None of this refutes my assertions. The biggest indicator of the flaws in your approach is the absolute and indisputable fact that many “black” populations in Africa are more closely related, in genetic ancestry, to non-“black” populations outside of Africa than to various other far-flung “black” populations.
Irrelevant straw-man nonsense. I haven’t asserted that nature does this in any way. Quit making up this irrelevant, straw-man bullshit. You just can’t get it through your head that this tells us zero – absolutely nothing – about the genes for intelligence among black people.
You understand that many people hold that this is false.
I’ve asked you stuff like this before, and you’ve ignored it – but I’ll ask you again. Do you hold that the above statement applied to the United States without regard to race in 1850? How about 1900? 1950? If not, why does it apply now? Why are you so damn sure that we’ve made society equal?
None of this conflicts with any of my assertions. I don’t believe “wealthy black parent just wants the kids to coast off the family dole” – I don’t believe “cultural crippling that prevents them from thinking Jimmy should keep his ass in school and learn”. It’s entirely reasonable and possible for rich black parents (and other black parents) to be great parents but society still throws obstacles in front of their children’s path to success that white kids don’t experience.
Again – do you think this (my proposed explanation) was possibly the case in 1850? 1900? 1950? If so, why is it so damn hard for you to admit that there might be the slightest chance it could still exist today?
I don’t either. This isn’t necessary for my proposed explanation.
Stuff like the recent Ferguson DOJ report, massive disparities in the justice system, and the like, seem to absolutely “rise to that level” (among other things) which might account for a (not “stubbornly persistent”, since a few decades is nothing in the scheme of human history) gap in outcomes.