As we know from natural experiment of Dutch famine of 1944 mother’s health is extremely important. This brief event had significant effects on two generations.
I get the impression that multi-generational effects don’t get into the popular press much. I’m guessing that people don’t want to think about problems which would take a long time to get better.
Do you know whether two generations was enough to undo all the effects of the famine?
Why’s that relevant, when the question is what parents can change by how they treat their children? (It would be highly relevant if the question were “how much of these differences are genetic?”, but on this occasion it isn’t.)
Looks (though I’ve barely skimmed it) like good evidence that twin studies say less than one might naively think. Doesn’t say anything about Caplan. Care to say a thing or two about what Caplan thinks twin studies say and how it differs from what analysis like that reveals that they say?
(Perhaps I’m just unduly lazy; I was hoping to find an easier way of assessing your claim versus Caplan’s than by procuring a copy of Caplan’s book, reading it carefully, reading a technical paper on twin studies, examining the particular studies on which Caplan’s claims depend, and comparing his use of them with the analysis in the aforementioned technical paper. Of course that’s the only way if I want to be really sure, but … well, I’m lazy and was hoping there might be a shortcut :-).)
Caplan’s claim doesn’t depend on this line of argumentation, but if it was true (which it’s not) it would make his point extremely strongly. Weaker claim that normal parenting styles don’t affect outcomes much, because the rest of environment (and genes) together have much greater impact is perfectly defensible.
Start here.
Also, twins share their uterine environment.
This wouldn’t apply to IVF twins reared apart, but I doubt there’s much of that in the studies.
As we know from natural experiment of Dutch famine of 1944 mother’s health is extremely important. This brief event had significant effects on two generations.
I get the impression that multi-generational effects don’t get into the popular press much. I’m guessing that people don’t want to think about problems which would take a long time to get better.
Do you know whether two generations was enough to undo all the effects of the famine?
It didn’t.
Why’s that relevant, when the question is what parents can change by how they treat their children? (It would be highly relevant if the question were “how much of these differences are genetic?”, but on this occasion it isn’t.)
I’m addressing the piece taw linked to, which was about flaws in studies of twins separated at birth.
Some degree of topic drift is normal here. Have you been in venues where all comments are supposed to address the original topic?
No, I have no problem at all with topic drift. It just wasn’t clear to me that that was what had happened. My apologies for any unnecessary confusion.
Caplan’s arguments are totally wrong, it doesn’t make his thesis wrong. I’d expect his thesis to be very likely to be at least mostly correct.
Looks (though I’ve barely skimmed it) like good evidence that twin studies say less than one might naively think. Doesn’t say anything about Caplan. Care to say a thing or two about what Caplan thinks twin studies say and how it differs from what analysis like that reveals that they say?
(Perhaps I’m just unduly lazy; I was hoping to find an easier way of assessing your claim versus Caplan’s than by procuring a copy of Caplan’s book, reading it carefully, reading a technical paper on twin studies, examining the particular studies on which Caplan’s claims depend, and comparing his use of them with the analysis in the aforementioned technical paper. Of course that’s the only way if I want to be really sure, but … well, I’m lazy and was hoping there might be a shortcut :-).)
You’re too lazy, no shortcuts this time.
Caplan’s claim doesn’t depend on this line of argumentation, but if it was true (which it’s not) it would make his point extremely strongly. Weaker claim that normal parenting styles don’t affect outcomes much, because the rest of environment (and genes) together have much greater impact is perfectly defensible.