@ indigo — 

Reading comprehension is highly g-loaded (e.g. the WISC-IV comprehension subtest correlates with g at the 0.73 level http://alpha.fdu.edu/psychology/wisciv_gloadings.htm), and the SAT verbal section mostly tests reading comprehension.

Most of the math in the SAT math section consists of routine application of algorithms, but some of the items involve problem solving, and a lot of the items involve twists and turns such that it's easy to make errors without good working memory, and working memory correlates moderately with g (e.g. reverse digit span correlates at the ~0.5 level).

Advising for gifted children available at Cognito Mentoring.