^^^^^^^ CB: And that the observable differences are entirely explainable by the adverse effect of racism on darker people and privileging effect on lighter people; not genetic differences, i.e. the observable differences are socially constructed not genetically caused. Just like racism explains the difference in average incomes between Blacks and whites.
In other words, all through life, from early childhood , in general, whites are given advantages by the institution of racism which causes them to learn better than Blacks the topics that are tested in IQ. As is said in the affirmative action debates, US society has comprehensive, cradle to grave, affirmative action in favor of whites , and has had for centuries. This explains the observable differences.
[WS:] I agree with you, but the point here is not to explain the difference, but to destroy its value as a justification for racism. Explaining won't do it. Breaking the implicit connection between the difference and its political interpretation as a predictor of life success will.
For example, one can argue by coming from the same premise as they do e.g. that certain cognitive abilities do predict success in the "western-defined world" and then list those cognitive abilities that are more visible in Blacks, e.g. what it takes to be a good football player - a good balance between strategic planning, team work and solidarity spirit (which BTW is highly valued in African countries), good psycho-motor coordination, and determination to persevere, and than make a claim that these skills are a better predictor of life success, everything else being equal, than a paper and pencil test. Of course, the argument is as crappy as that making a similar claim based on IQ test results, but it puts the IQ crowd in the defensive and forces them to make claims that make them vulnerable - namely that IQ matters more than the aforementioned battery of characteristics.
PS. Differences in human skills abilities are quite normal and do not determine life success. For example, I am reasonably good at analytical tasks, but cannot sing or dance to save my life. That does not make me more successful in life than most performers, who are more popular and often better paid.
Wojtek