IQ subtest scores are not increasing at the same rate

In this very interesting post by Steve Sailer on James Flynn's (of Flynn Effect fame) on his new book, What is Intelligence? Beyond the Flynn Effect, I noticed something regarding the Flynn effect I never noticed before. Namely, that while IQ's have been on the rise, not all aspects of IQ have been rising at the same speed. The three slowest areas of improvement are for information, arithmetic, and vocabulary, and comprehension.

I don't think it's a coincidence that these four areas involve some aspect of academic content while the remaining faster growing areas generally do not.

According to Flynn, massive IQ increases are not seen in all types of cognitive functioning, just in a couple of areas, which explains why kids these days don't seem all that much smarter, except at programming their new gadgets. The Wechsler Intelligence Scale for Children (WISC) is one of the most popular IQ tests. Here are its ten subtests, ranked in order from smallest to largest IQ gain over 55 years:

WISC Subtest	IQ Gains in Points 1947-2002	Sample Question
Information	2	On what continent is Argentina?
Arithmetic	2	If a toy costs $6, how much do 7 cost?
Vocabulary	4	What does "debilitating" mean?
Comprehension	11	Why are streets usually numbered in order?
Picture Completion	12	Indicate the missing part from an incomplete picture.
Block Design	16	Use blocks to replicate a two-color design.
Object Assembly	17	Assemble puzzles depicting common objects.
Coding	18	Using a key, match symbols with shapes or numbers.
Picture Arrangement	22	Reorder a set of scrambled picture cards to tell a story.
Similarities	24	In what way are "dogs" and "rabbits" alike?

We see only small changes in the first three mental skills: general knowledge, arithmetic, and vocabulary. And
yet these are the skills that come up most in our casual conversation

However, there have been substantial improvements in the next six subtests, most of which involve visual logic. The proliferation of visual imagery was one of the major changes in the social environment in the 20th Century. People have much more practice at decoding images quickly than in the past.

Catherine here, diving into Ken's post.

This is the "fuzzy math makes you smarter" issue. All of those "find the pattern" constructivist math textbooks resemble the items on the Ravens Progressive matrices.