Back to IQ,
Black Americans reduce the racial IQ gap: Evidence from standardization samples (Psychological Science, Oct '06) states that the tested IQs of black Americans has been on a sharp rise over time, narrowing the "IQ gap" with whites by upwards of 7 points in the last three decades. Although all IQ scores rise over time among groups (the "Flynn effect"), those among blacks have outpaced the average gains by whites at a predictable rate. See also
Black-White Gap In IQ Scores Closing (Issues in Higher Education Aug '06). According to research at Washington University in St. Louis, black students show four times the IQ gain shown by white students while in college (The Journal of Blacks in Higher Education, Dec '97).
In 1951, testing of black and white infants actually concluded that black (American) infants were
smarter than white infants although not by a notable amount (
Socio-economic status and race as factors in infant intelligence test scores, Child Psychology 1951). This advantage was born out in three different tests. See also
Longitudinal Assessment of the Intelligence of Black Infants (National Inst. of Child Health and Human Development, '79)
In 1986,
The Minnesota Adoption Studies: Genetic Differences and Malleability (Child Development, April 1986) was published in which IQ scores among black infants adopted into white families were compared with those of other groups. Among its findings:
Quote:
Both the parents and the biological children of the families scored in the bright average to superior range on age-appropriate IQ tests. The black and interracial adopted children were also found to score above the average of the white population, regardless of when they had been adopted. The black children adopted in the first 12 months of life scored on the average at IQ 110 (Scarr & Weinberg, 1976), 20 points above comparable children being reared in the black community. We interpreted the high IQ scores of the black and interracial children to mean that (a) genetic racial differences do not account for a major portion of the IQ performance difference between racial groups, and (b) black and interracial children reared in the culture of the tests and the schools perform as well as other adopted children in similar families
Granted, we're talking about African-Americans in these studies and not "legitimate" sub-Saharan Africans. Which was a point studied in
Absence of a relationship between degree of White ancestry and intellectual skills within a Black population (Human Genetics, 1977) which found a lack of correlation between the intelligence scores of African-Americans and the 'purity' of their African ancestry vs those who experienced some European interbreeding. In other words, you can't explain away higher scoring blacks by suggesting that they must have some European blood in them. It's also interesting because in IQ tests done on sub-Saharan Africans (in this case, from Zimbabwe), the Africans scored two standard deviations lower than Europeans, however African-Americans only scored one deviation lower.
African–White IQ differences from Zimbabwe on the Wechsler Intelligence Scale for Children (Personality & Individual Differences, Jan '03)
Cross-cultural Effects on IQ Test Performance: A Review and Preliminary Normative Indications on WAIS-III Test Performance (long title, huh? From Journal of Clinical & Experimental Neuropsychology in Oct '04) found that black South Africans who were tested in African and who had advantaged education opportunities (i.e. not stuck as blacks in the S. African public education system) scored similarly to white Americans.
The study wrote:
Scores for the white English and black African first language groups with advantaged education were comparable with the US standardization, whereas scores for black African first language participants with disadvantaged education were significantly lower than this.
[...]In sum, it appears that when black African first language individuals who are proficient in English have been exposed to high quality of education, they are able to perform at a level broadly equivalent to the U.S. standardization.
If African-American test scores are not linked to the directness of their African ancestry and if African-American test scores have shown a continual improvement which far surpasses the rate of white improvement,
and if infants of African descent are no less intelligent than white infants, it would seem unlikely that there is a strong genetic component to African intelligence (as a whole) vs that of other races. Rather, environment seems to play a role which dwarfs any minor effect genetics may have.
Gbaji wrote:
3. Do groups within a single species tend to develop different "common" genetic traits over time when separated genetically from eachother?
Yes or no.
Don't answer no. Darwin would be sad...
Darwin would be even sadder to see you using only half of his concept. Groups tend to diverge when they are geographically isolated
and when the divergence is of a survival benefit. You are, although you deny it, asking people to accept that (a) every group of sub-Saharan Africans, no matter how interbreeding or isolated, evolved along the same genetic path in regards to intelligence and that (b) in none of these groups was greater intelligence enough of a survival benefit for it to flourish in the gene pool. But only in sub-Saharan Africa.
Now
that would make Darwin sad.
Quote:
I never used the word "inferior". That's your word, not mine.
Actually, that was Watson's word.
Although it may be easy to frame this as a "political correctness" issue, the fact is that there are a lot of reasons from a critical standpoint to doubt that there are continentally broad and notable genetic difference in intelligence potential among sub-Saharan Africans versus whites or whoever else. Extraordinary evidence is needed for these claims, not half-cocked theories about Darwinism and insinuations that any resistance is due to political correctness.
Edited, Oct 21st 2007 2:24pm by Jophiel