I would imagine that it is easier to acknowledge the differences when you have been blessed with being on the right side of the bell curve, so to speak.
There are bell curves for lots of things apart from cognitive ability. Athletics springs to mind. I expect that parents of truly gifted athletes experience the same feelings of discomfort that most or all of us do when they interact with parents who mistakenly believe that their kids are gifted at running or basketball or whatever. At the same time, no one would deny that some kids are just much better athletes than most other kids.
...the question at the center of the Bell Curve debate: is the proven ability to do or not do advanced work the result of genetic differences that underlie intelligence or something else.
I've re-read Chapter 13 in
Bell Curve ("Ethnic Differences in Cognitive Ability"). The conclusion of the authors seemed to be that the answer is "both."
Their evidence for population-based genetic differences in cognitive abilities seemed pretty solid to me. Their main point in support a role for genetics was that subtest scores among different ethnic groups have similar patterns.
Here are two examples of their evidence:
1. IQ tests have consistently shown that East Asians get higher scores on subtests measuring visuospatial abilities. The book asserts that this is why there are so many Asian people in science and engineering. But there's more...
"East Asians" includes people living in East Asia now and in those adopted into white families here (e.g. Korean infants). It also includes people whose predecessors moved to the United States --- whether the predecessor moved here last year or via the land bridge over what is now the Bering Strait. I think this is fascinating:
The Bell Curve cites a review of studies showing that subtest scores for Inuit people and other native Americans mirror those of contemporary East Asians. (Locations 5270 - 95 on my Kindle copy of the book).
2. Another study compared two caucasian- and African-Americans with the roughly the same IQ scores. They found that even though everyone involved had about the same overall score (105 is cited), the patterns for subtest scores differed between the two ethnic groups. Caucasians had one pattern of strengths and weaknesses, and African-Americans had another. This comparison used only the overall IQ score as a criterion for entry, and members of each group were from every socio-economic class.
The book also cites evidence for environmental factors. It seems that the gap between African-American and caucasian-American scores had closed between 1950 or so and 1990. The difference was a few points-ish. The narrowing gap was due to higher A-A IQ scores and not to lower C-A scores. A substantial portion of the first part of the chapter discusses this idea. Okay, I have to cut this short; more later.
Overall, the authors argue that environment and genetics are both factors in IQ.
Must go; my kids need lunch!
Val
