I can share in the incredible frustration I sense Lex felt in this podcast on the discussion of intelligence with Haier. So much of Haier’s opinion is formulated on old studies done decades ago. he’s retired now.  Given his stance, no justification is given for the Flynn effect, no acknowledgement of the role of curiosity in learning and intelligence  or how recent advances in our understanding in <b>how</b> we learn (spaced repetition, method of loci and other new learning formats., may play a role in the fluidity of intelligence). As a physician that has gone through many years of schooling so far, if standardized tests are highly correlated with the G factor that further weakens Haier’s argument because many pre-meds/pre-law students are able to significant improve their scores over time—which according Haier, should be unlikely because the G-factor is supposedly static. This was an interesting topic, but this was an incomplete discussion with many loose ends.,(reply>), The Lothian birth cohort study is still ongoing. They have several “generations” of old 11+ scores available — those were the “intelligence tests” that Haier mentioned early in the interview. The oldest test takers are pretty much dead now but they are studying the next cohorts now. It is still the case that the lowest scorers die first and that the highest scorers are healthier and have better lives.<br><br>Haier misrepresented the origin of the tests, though. The kids were not tested to satisfy intelligence researchers but to sort them into 2 or 3 types of schools, according to their talents.<br><br>The Flynn effect is known to have been stronger for people at the low end of the scale and practically non-existent at the high end — so a likely cause is better health for the poor. It is also known to be (much) stronger for some IQ tests than for others — with the obvious possibility being that they are more trainable and that school trains better them now than it used to. Raven’s progressive matrices shows a particularly large Flynn Effect.<br><br>A recent study of about 4000 random people in England, who were given IQ tests and whose DNA was scanned on DNA chips (which checks for common single-nucleotide polymorphisms, that is, differences), showed that the correlation between people’s DNA similarity and their IQ similarity also exists for really small DNA similarities and for which “the environment” cannot be used as an excuse. In other words: we know intelligence is real, we know it can be measured, and we know that it has a large genetic component. I think it was published by Robert Plomin.,(reply>), You may be interested in learning of the reverse Flynn effect. "The Matter With Things, Chapter 7, Iain McGilchrist"