Saturday, October 18, 2008

The joy of Turkheimer







Gloomy Prospect Wins

slides (ppt) , iTunes audio




There are a large number of potential causes.

The potential causes are non-independent.

Randomized experimentation is not possible.




Anonymous said...

Also see his wonderful essay The Fundamental Intuition (at Cato Unbound).

Carson C. Chow said...

Hi Steve,

So it seems by Turkheimer's work that intervention at the lowest rungs of the economic ladder would have the biggest effect on the future prospects of a child. By this argument, we should pour resources into programs for the very poor.

On the flip side, what does the data say on programs for talented and gifted children? Do children that come out of these programs go on to higher achievement than children that do not? Given that environment may not enhance IQ once you are beyond a threshold, it could influence other things like exposure to like-minded peers, ideas and tools for maximizing their talents. This may not make you smarter but does it make you more productive?

Anonymous said...

It's good to see social scientists like Plomin finally realizing the inherent limitations and "gloominess" of using genetics in explaining complex social traits. He could have simply walked down to the molecular biology department and asked a working geneticist or walked to the philosophy department and asked to speak with a philosopher of science specializing in the philosophy of biology. He would have been set proper long ago.

Though my speciality is not philosophy of biology, I am studying philosophy and know of some work that has been done in the area of philosophy of biology.

For example, this paper by Ned Block is a rewrite of an earlier one he wrote from the early 70s detailing the inherent limitations of heritability.

This book was written about ten years ago and it touches on the explanatory limitations built into both classical and molecular genetics in its use in the domain of social science.

I agree with Sarkar that classical genetics will never give any meaningful, nontrivial and scientifically significant explanation of any complex trait. Molecular genetics is similarly handicaped as of now and even in the far future. it almost certainly will not yield major results in explaning the vast majority of complex traits. This is simply built into the nature of the science of genetics and its relation to social science.

Ben017 said...


A few points:

1 - The study included only young children and does not make any attempt to extrapolate that all other findings of significant increases in h^2 by age 17 are in any way invalid. The effects of the shared environment vanish at around age 12.

2 - Turkheimer began his paper by recognizing that the heritability of cognitive ability in childhood is well established.

3 - Turkheimer made no attempt whatsoever to determine what components of SES he was measuring. There are three obvious items to consider: macro environmental, micro environmental, and genetic. All work to date indicates that the first of these can be found in children, but that it is absent in late adolescents; by late adolescence, all of the environmental component is of the second type; and that genetic intelligence is the largest determinant of SES.

4 - Turkheimer says that the effect he observed was related to the homes in which the children were raised. This is interesting, since it relates to the adoption studies which show that after childhood there is no adult IQ correlation between biologically unrelated children who were reared together in the same home.

5 - Turkheimer discusses in some detail that SES is not strictly an environmental variable, since it is known to be (statistically) caused by the intelligence of the parents. He points out that the models he used "cannot determine which aspect of SES is responsible for the interactions" observed.

Frank Pasquale said...

Thank you very much for transcribing Turkheimer on the nature of social science...I was dreading having to re-listen to that podcast to get the quote for a paper I'm writing!

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