Sensible hypothesis: cognitive abilities vary

The newest issue of Nature has no less than eight correspondences on the topic of studying race differences in IQ. I wrote about this earlier, presenting Steven Rose's view, and then never got around to dealing with the other point of view. The discussion has been raging on Nature's public opinion forum, and for that reason I didn't feel like writing any further about it here. But one of the views today nicely sums up what i think of the matter, so I quote it here in full.

Nature 458, 145 (12 March 2009) | doi:10.1038/458145b; Published online 11 March 2009

Identifying adaptive differences could provide insight

Kathryn Holt1

1. Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
Email: kh2@sanger.ac.uk

Sir

With regard to the Commentary by Steven Rose, Stephen Ceci and Wendy M. Williams 'Should scientists study race and IQ?' (Nature 457, 786–788; 2009 and Nature 457, 788–789; 2009), I agree with others who have said we should not expect different subgroups of the human population, evolving independently, to arrive at exactly the same place in terms of cognitive abilities. This makes no more sense than expecting different populations to end up identical in skin colour, stature, metabolism or other aspects that are easily understood as adaptations to different environments.

So, given that we have logical reason to hypothesize about differences in cognitive abilities, why would we expect to measure these by using a single number such as IQ, which suggests there must be a hierarchy of cognitive function? The prediction surely is that each population will adapt to be better at the particular cognitive tasks that are most important for survival in its own environment. If this is the case, then identifying these (potentially adaptive) differences in cognitive ability, and searching for associations with genetic variants, could provide fascinating insights into how our brains work.

However, this is worlds away from measuring IQ of different 'race' groups in order to make claims about genetics and intelligence. There may be some value in these rather simplistic studies of race and IQ. But they do nothing to answer the scientific question of the genetic basis of intelligence and can easily be hijacked by individuals to advance their own prejudices.

The article is here, and at the bottom of it are links to the other seven contributions to the debate today.