Your “Page Not Found” argument is persuasive.
These “West Africans” - do they include the Mbuti?
I haven’t found a link to the original paper yet, but here’s what I have: http://www.eurekalert.org/pub_releases/2009-12/uop-gsc121809.php
Does this work for you? (Tested and works for me).
OK, so let’s examine this, to see if we can find testable implications.
For our hypothetical “negative intelligence” gene, which of the following statements do you believe to be accurate:
a) anyone with any West African heritage at all will be affected by the negative intelligence gene (and will have an average IQ of 85)
b) The more West African heritage a person has, the more likely they are to be affected by the negative intelligence gene. Those affected will have an average IQ of 85 and those unaffected will have an average intelligence of 100
c) Anyone with any European heritage at all will be unaffected by the negative intelligence gene
d) Other
I guess I’d go with b) and add that for that hypothesis to work (i.e., for the negative intelligence cluster to have spread through the whole or most of the West-African population), it would have to confer some other advantage.
And there’s the other “synthetic evolution” theories, that just randomly, West-Africans became dumber over time (seems highly unlikely), or somewhat more possible, that we know humans started in East Africa, and the first few guys who migrated to the West just happened to be idiots (i.e., Founder’s Effect).
OK, so this has testable implications. Consider the following:
So, for any group of people with mixed West African and European heritage, the *average *IQ will be between 85 and 100, furthermore the *average *IQ will increase as the proportion of European heritage increases. This is because a higher percentage of the tested people will have average IQs of 100 compared to 85.
Do you agree this is the logical and testable result of the assumptions?
I’m waiting with bated breath for you to whip out the study which disproves the hypothesis you’ve set up…
of course (but I should point out that I’ve already cited it earlier in this thread.)
Does this mean we agree that the data doesn’t support the claim that there is a genetic link between West African heritage and IQ?
I mean, we’ve started with the asssumption that there is a link, determined that there are testable implications of this assumption, and are now prepared to test that assumption. As scientfically-minded people, shouldn’t we conclude that, if the data doesn’t support our assumptions, that our assumptions are incorrect?
I painstakingly went through all four really long pages of posts and couldn’t find it (Southern Poverty Law Center? MSNBC? “Most psychologists agree?”)
If there was good data, I’d certainly agree with everything you’re saying. But… good data in this area is really hard to find. Almost all of it, on both side, seems to be agenda-driven and flawed in one way or the other.
(Data on south-Asians seems to be least biased, for whatever reasons.)
It comes from the Minnesota Transracial Adoption Study, which tested average IQ against genetic tests of African heritage and found "All of the children in our study were socially classified as black but differed individually in their proportion of African ancestry. We found no relationship between blood group and serum protein markers of African ancestry and cognitive test scores. If more African ancestry is not related to lower scores among socially-classified blacks, then African ancestry can hardly be an explanation for IQ differences between black and white groups. "
You said:
So, what’s your conclusion?
I think you’ve chosen to wrong study. Here’s a summary of Scarr’s work from an objective source:
Scarr studied 130 black/interracial children adopted by **advantaged **white families. She found that the black subjects did score above both the IQ. mean and school achievement average of the white population, but they did not, however, “perform as well as either the adoptive parents or their biological children” (Scarr, 1976, p. 731). Scarr estimated that heritability of IQ. lies between .40 and .70 and that IQ. scores are highly malleable because of environmental factors that affect a child’s development.
While the black adoptee’s did outperform white population on average (I guess arguing for role of environmental enrichment, motivation and preparation in test-taking), they were inferior to the biological children raised in the same household (i.e., who presumably had same motivation to do well on test, and same overall level of “enrichment”).
This seems pretty conclusive in direction opposite from what you were trying to say.
Here’s the website (which, btw, concludes “this debate may never be resolved.”)
http://academics.hamilton.edu/government/dparis/govt375/spring97/Race&Testing/rt3.html
Now that I think about it, maybe not. Since maybe the fact that it was an “advantaged” family, means they were above-average in intelligence to begin with.
Perhaps only way to answer this definitively is for some totalitarian regime to invade the U.S. and then run some horrible, unethical experiments on the enslaved population.
P.s., I’ve also heard it argued that “whites” who immigrated to U.S. in late 1900 and early 20th century were the on the low end of intelligence (some tests given to WW I infantryman showed most could be classified as “imbeciles”), so comparing adoptees to “white population” may be comparing them to a below-average group.
Do you think that comparing black adoptees to white adoptees is the same as comparing black adoptees to each other based upon their ratio of African heritage?
Pop quiz: If some tests given to WW I infantryman showed most could be classified as “imbeciles”, which is more likely:
a) “Whites” who immigrated to U.S. in late 1900 and early 20th century were the on the low end of intelligence
b) The IQ tests of the era didn’t accurately measure intelligence
If it helps, think of the above as an intelligence test.
I think for all these sort of epidemiological studies, it’s a game of averages. So, if you’re trying to test the hypothesis that West-Africans tend to be lower in intelligence than Europeans, then comparing white and black adoptees seems the “purest” study you’re going to get.
Ratio of African heritage just sounds confusing–based on what measure?, who knows if the “intelligence” genes really are dominant or would likely get lost in intermarriage, who knows if blacks who tend to marry whites tend to be descended from a certain West-African group, etc. etc.
Yeah, I was just offering that tidbit as a bit of entertainment. I think the infantrymen being tested were comprised mostly of recent immigrants, and whoever was administering the test probably didn’t have strong positive feelings for these immigrants, which was probably reflected in the test scores.
Never mind, my error; I linked to the wrong study. I should have linked to Scarr, Pakstis, Katz and Barker. I can’t find an online link, but see: http://books.google.com/books?id=UW9cjBo_nCIC&pg=PA147#v=onepage&q&f=false:
No, because it won’t enable you to distinguish between genetic and environmental impacts. If black people perfom poorly on IQ tests because of low expectations, then an adoptee study won’t remove that impact. If you’re testing for impact of genetics you need a test that measures genetics. As we discussed.
None of these objections passes my smell test.
If you think “blacks who tend to marry whites tend to be descended from a certain West-African group” then support that. We have genetic tests that can ferret that out.
If you think “Ratio of African heritage just sounds confusing,” then I guess you’ll have to put your faith in the geneticists who aren’t confused.
If you think that “who knows if the “intelligence” genes really are dominant or would likely get lost in intermarriage” then I suggest you show me how that would invalidate the test.
Meantime, the actual evidence shows so genetic link between West African heritage and IQ.