This is why papers like H. Rindermann, Relevance of Education and Intelligence for the Political Development of Nations: Democracy, Rule of Law and Political Liberty, Intelligence, v36 n4 p306-322 Jul-Aug 2008 are relevant. This one looks at lagged data, trying to infer how much effect schooling, GDP and IQ at time t1 affects schooling, GDP and IQ at time t2.

The bane of this type of studies is of course the raw scores - how much cognitive ability is actually measured by school scores, surveys, IQ tests or whatever means that are used - and whether averages is telling us something important. One could imagine a model where extreme outliers were the real force of progress (I doubt this one, given that IQ does seem to correlate with a lot of desirable things and likely has network effects, but the data is likely not strong enough to rule out an outlier theory).