Pablo comments on Using a memory palace to memorize a textbook.

[Pablo]

Great post.

Gwern points to expert opinion that visual thinking ability might be second only to IQ in terms of intellectual importance.

Do you happen to remember the source for this? A quick Google search didn’t help.

EDIT: Found it (I think):

an emphasis on spatial reasoning & visualization ability was one of the reasons behind SMPY choosing to use SAT-M for screening, as one of the theses is that, after general intelligence, visuospatial reasoning (as opposed to the more academically-prized glibness & verbal ability) may be the next most important requirement for major STEM achievement.

[DirectedEvolution]

Yep that’s the one!