This is one of the best literature reviews I've ever seen, on any topic. It's comprehensive, straight-to-the-point, focused on empirical evidence, clearly written.

TL;DR: intelligence is real, it is not that hard to measure, it is not a proxy for parental income, it is largely inheritable, it correlates with brain size and anatomy, it predicts important life outcomes (like academic and professional success), it differs across races in ways that cannot be attributed to environmental influences (though the distributions largely overlap and there are people of all races in all intelligence brackets). Also, Gardner's multiple intelligences theory is not falsiable (which makes it less scientific than, say, astrology).

There are a few wrinkles. Most importantly, the Flynn effect. Warne attributes it to abilities that are not related to general intelligence. But this (if correct) has important implications - maybe IQ tests need to be improved, etc - that Warne doesn't fully consider.

Also, the final chapters are a bit "meh". They are philosophical in nature, so there isn't much to engage with. (It's interesting though that in a parallel universe IQ research could be a left-wing niche - IQ differences are real and genetic and therefore weaken the "they just need to work harder" worldview.)

Overall though this is an amazing book. It should be an essential reading for policymakers, but I suspect policymakers are among the least likely to ever hear about it, let alone read it. ( )

Amazing collection of references

I'm often asked for sources when discussing intelligence research. Unfortunately, I don't index what I read.

Here it is. Oh, bliss, oh, joy! ( )