I wish Lex would have let Richard explain how one rigorously establishes causation from correlations. The G-factor is a measure of correlation that is sufficiently general to persist in all cases(or so it seems), so using such a measure might be the basis of a causal understanding. If this is the case, what are the the appropriate constraints on the conclusions derived from these largely statistical axioms rather than directly causal ones. Generally truths uncovered by a battery of correlation measures are the weakest ones one can make, and are ripe for the misappropriation of cause which has very real damaging consequences to society. Truth is never dangerous, but especially in fields like this we only get poor approximations, these certainly can be. I would advocate for an understanding of intelligence based the universality of man; a bottom up approach. I am skeptical that a sociological understanding of intelligence could ever lead to anything more than sociological observations, which will never be useful to issues facing individuals. Scale matters. <br><br>This is perhaps why the nobel Laurette  said you dont want to go there, because we dont have the means to make it precise enough for its benefits to outweigh the harms.