I have been musing over the results of Rindermann, Coyle and Becker’s survey of intelligence experts presented at the ISIR conference. It looks as if many of the invited participants turned down the invitation. It may have been caution on their part that the survey would not remain anonymous (people can lose their jobs just for reporting intelligence results on group differences) or perhaps they were put off by the format and length (62 main questions) or even the idea of trying to investigate underlying opinions in a way that might lead to a conclusion “experts agree that…..”
You will already know that a general theme of this blog is that humans are a pesky lot, and difficult to study. They don’t fill in questionnaires, they forget about how much chocolate they eat, they look with envy at their neighbour’s wife, and very probably his ox, and have strong opinions, secret thoughts, impossible dreams and some highly questionable habits. Experts seem to be just as pesky. Drosophila are much better. Fruit flies are the future.
On another sour note, how does one qualify to be an expert nowadays? Publishing a recent paper in a peer-refereed journal is certainly a start, and should put you ahead of most of the multitude of commentators, journalists and citizens who knew a bright guy in their class who couldn’t tie his shoelaces, but is it enough? Can we be sure these 228 authors have done the necessary reading? Should we start getting into impact factors and other measures of expert worthiness? Best of all, should we just ferret out the best papers with the best arguments, and tell students that, until they can be torn down, those papers presents the best approximation to the truth?
Anyway, here is the US centric question on racial differences in intelligence (there are other places on the planet like Brazil with different races living together, and there is also Africa, but once again the US leads the news).
Personally, having looked at the literature off and on for 40 years, and more of it in recent years, I cannot see how anyone can really believe that none of the difference is due to genes or that all of the difference is due to genes. I mean, the tiniest contrary finding would prove you wrong. A few genes linked to brain even in a minority of cases, a few environmental toxins linked to brain in a minority of cases and the presumption would be falsified. How could one be “expert” and be so sure of one’s self, given that there is an error term in all investigations?
For example, there is general agreement in this sample (though not universal agreement) that there is strong evidence for the heritability of intelligence within genetic groups. Given a proven cause of intelligence from genes, how could one be so sure that the difference between genetic groups will have no genetic component? It is not proven thereby, but certainly not disproven, and the possibility remains open, and can be investigated by genetic research.
Equally, given that we can show a likely effect on intelligence of very bad environments, how can one be sure that all the effect is genetic? Jensen, for example, thought the difference was 50% genetic, and then over the years raised that to about 70% genetic (in the US context). All these estimates depend on the circumstances in which the measures are taken. Universally provided reasonable environments boost the genetic estimate by reducing environmental effects. Reduce the quality of the environment, and it jumps back into the equation with a vengeance.
I think that it is the central section in blue which represents main stream opinion among experts, which is those who did not say 0 or 100. Of those, 40% say up to 40% of variance is genetic, 40% say it is as high as 60-100 genetic, and the remaining 20% are in the middle at 50%. This is a split jury in terms of the extent of genetic influence, but the general tendency is towards agreement that genes are involved to some extent. That is a useful finding.
The paper will be presented for publication soon enough, and then we might speed up the tempo of surveys, to say every 5 years or so. Perhaps there needs to be fewer questions and even more consultation with the relevant experts about what should be included. Perhaps there should be even more stratification of experts, setting the bar higher in terms of number of publications on intelligence. However, we are now in a better position to know what experts really think, and that is a very valuable addition.