The right question to ask depends on what you want to know. “Success”, “contribution”, “greatness” are in themselves not quantifiable. You have to change these terms into something quantifiable, that will necessarily come with a different meaning. I do not pretend that I can provide a quantifiable, universal definition for these terms that will satisfy everyone. For example, a measure of success is remuneration, so you may want to ask whether higher paid scientists have correlated higher IQ, and the answer to this would be yes (this is true to almost all occupations). But you may think that salary is not a good enough measure for scientific success, so you may want to go a different route, say, Nobel prize winners, but immediately the exclusion of the peace nobel comes to mind, as it is more political than academic in nature. So what do you want to know, really? What my line of inquiry would be, following what I understand to be the interesting question here (and you may disagree), is to: (1) limit the question to academia (2) not exclude any fields, even from humanities (3) define success by number of published papers weighted by number of citations, as a ratio, to remove length of career as a factor (4) compare IQ to average of the field, not absolute values. I believe this would yield potentially interesting results, but I doubt any such research has been done.