re: Why Scientists and extremely smart people are usually socialist/leftist

Well IQ tests are norm-referenced by age groups. Besides in any IQ measure, a young adult would have any advantage over a child; it's not specific to general knowledge.

Besides although part of Crystallized intelligence is retention of knowledge, it also refers to vocabulary and verbal reasoning. But it's just one (albeit an important one) of a number of broad abilities that have been studied extensively and is a component of almost all (some nonverbal assessments aside) IQ tests.