I don’t think there are that many that reliably affect adult IQ, and what we’re interested in is the retest correlation of IQ among adults.
Yep. 0.8 is retest correlation among adults. Also, like, I don’t know of any big studies that tried to increase adult IQ with anything that doesn’t seem like it’s just obviously going to fail. There are lots of “here is a cheap intervention we can run for $50 per participant”, but those obviously don’t work for any task that already has substantial training time invested in it, or covers a large battery of tests.
Lynn is pretty sure it’s not just education, as children before they enter school show the same sorts of improvements.
Yep, definitely not just education. Also lots of other factors.
Hard to say, actually; I think the instantaneous retest correlation is higher for IQ tests than it is for basketball skill tests (according to a quick glance at some studies), and I haven’t yet found tests applied before and after an intervention (like a semester on a basketball team or w/e).
One of the problems here is that IQ is age-normalized. In absolute terms you are actually almost always seeing very substantial subcomponent drift and changes, the way they change just tend to be correlated among different individuals (i.e. people go through changing in similar ways at the same age). This exaggerates any retest-correlations compared to a thing like a basketball test, which wouldn’t be age-normalized.
To make my epistemic state here a bit more clear: I do think IQ is clearly less trainable than much narrower skills like “how many numbers can you memorize in a row?”. But I don’t think IQ is less trainable than any other set of complicated skills like “programming skill” or “architecture design” skill.
My current guess is that if you control for people who know how to program and you run a research program with about as much sophistication as current IQ studies on “can we improve people’s programming skills” you would find results that are about as convincing saying “no, you can’t improve people’s programming skill”. But this seems pretty dumb to me. We know of many groups that have substantially outperformed other groups in programming skill, and my inside-view here totally outweighs the relatively weak outside-view from the mediocre studies we are running. I also bet you would find that programming skill is really highly heritable (probably more heritable than IQ), and then people would go around saying that programming skill is genetic and can’t be changed, because everyone keeps confusing heritability with genetics and it’s terrible.
This doesn’t mean increasing programming skill is easy. It actually seems kind of hard, but it also doesn’t seem impossible, and from the perspective of a private individual “getting better at programming” is a totally reasonable thing to do, even if “make a large group of people much better at programming” is a really hard thing to do that I don’t have a ton of traction on. I feel similarly about IQ. “Getting better at whatever IQ tests are measuring” is a pretty reasonable thing to do. “Design a large scale scalable intervention that makes everyone much better” is much harder and I have much less traction on that.
Yep. 0.8 is retest correlation among adults. Also, like, I don’t know of any big studies that tried to increase adult IQ with anything that doesn’t seem like it’s just obviously going to fail. There are lots of “here is a cheap intervention we can run for $50 per participant”, but those obviously don’t work for any task that already has substantial training time invested in it, or covers a large battery of tests.
Yep, definitely not just education. Also lots of other factors.
One of the problems here is that IQ is age-normalized. In absolute terms you are actually almost always seeing very substantial subcomponent drift and changes, the way they change just tend to be correlated among different individuals (i.e. people go through changing in similar ways at the same age). This exaggerates any retest-correlations compared to a thing like a basketball test, which wouldn’t be age-normalized.
To make my epistemic state here a bit more clear: I do think IQ is clearly less trainable than much narrower skills like “how many numbers can you memorize in a row?”. But I don’t think IQ is less trainable than any other set of complicated skills like “programming skill” or “architecture design” skill.
My current guess is that if you control for people who know how to program and you run a research program with about as much sophistication as current IQ studies on “can we improve people’s programming skills” you would find results that are about as convincing saying “no, you can’t improve people’s programming skill”. But this seems pretty dumb to me. We know of many groups that have substantially outperformed other groups in programming skill, and my inside-view here totally outweighs the relatively weak outside-view from the mediocre studies we are running. I also bet you would find that programming skill is really highly heritable (probably more heritable than IQ), and then people would go around saying that programming skill is genetic and can’t be changed, because everyone keeps confusing heritability with genetics and it’s terrible.
This doesn’t mean increasing programming skill is easy. It actually seems kind of hard, but it also doesn’t seem impossible, and from the perspective of a private individual “getting better at programming” is a totally reasonable thing to do, even if “make a large group of people much better at programming” is a really hard thing to do that I don’t have a ton of traction on. I feel similarly about IQ. “Getting better at whatever IQ tests are measuring” is a pretty reasonable thing to do. “Design a large scale scalable intervention that makes everyone much better” is much harder and I have much less traction on that.
I think laying out your thoughts on this would make a great top-level post. Starting from your comments here and then adding a bit more detail.
Do you happen to remember the source for this? I’m having trouble finding any studies that seem to bear directly on the question.