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> Even children born to high-IQ parents are slipping down the IQ ladder. It is expected that the children of high IQ parents have lower IQs than their parents
by mattnewport 7y ago
> Even children born to high-IQ parents are slipping down the IQ ladder.
It is expected that the children of high IQ parents have lower IQs than their parents (and that children of low IQ parents have higher IQs than their parents). That is just regression to the mean. How are they separating this from that effect?
- clairity 7y ago> "That is just regression to the mean." that would certainly be true if IQ were independently and identically distributed (iid), but the point here is that IQ is hereditable (not independent nor uniformly distributed) and so should show, in the long run, measurable durability in those differences across lineages. it's likely not reversion to the mean (or more to the point, the mechanism is not simply statistical in nature).
- ctlby 7y agoYou're confusing concepts. Regression to the mean doesn't depend on any IID assumption. Conditional expectations are right in the definition! In the bivariate normal case (height, intelligence, etc), it's a necessary consequence of a correlation coefficient < 1.
- rockinghigh 7y agoWouldn't parents with low IQ also have children who regress to the mean and have higher IQ?
- tomerico 7y agoThey would. that is what happens with any heritable trait. It's clearly documented for example for height.
- thfuran 7y ago>It is expected that the children of high IQ parents have lower IQs than their parents Is it? Hadn't IQs been trending upwards for the past several decades?
- pixl97 7y agoYes, but a lot of that was likely based on improving diets, especially during childhood.