Article: After the Bell Curve

[Barry Desborough]

I'd always suspected that the twin studies used to draw conclusions about IQ and heredity had a problem. In an evironment that allows for the full development of genetic potential, much of the differences in IQ can be ascribed to genes. But in the cases where the environment is inadequate, this does not necessarily apply. I've had exchanges with Charles Murray and other 'IQ and genetics' guys over this. They dismiss the point by saying that only in cases of extreme deprivation and abuse does the environment have such a significant impact.

This work by Eric Turkheimer, described by David Kirp, suggests we need a more subtle approach to studying the nature-nurture issue.


Turkheimer, a psychology professor at the University of Virginia, is the kind of irreverent academic who gives his papers user-friendly titles like “Spinach and Ice Cream” and “Mobiles.” He also has a reputation as a methodologist’s methodologist. In combing through the research, he noticed that the twins being studied had middle-class backgrounds. The explanation was simple — poor people don’t volunteer for research projects — but he wondered whether this omission mattered.

Full article (http://www.nytimes.com/2006/07/23/magazine/23wwln_idealab.html?pagewanted=1&_r=2&ei=5090)

Copyright (c) New York Times Magazine/David L. Kirp

[Tladatsi]

I don't disagree with your point, I believe it is certainly true. I have posted several times on this site clarify that simply having a gene does not that that gene is expressed.

However, the point I find more interestings is - so what? What does IQ measure but your ability score well on IQ tests? Even if there was a single "thing" called intellegence, which I don't believe is the case, and even assuming that IQ tests measured this intellegence, of what interest is it?

I know a fellow who is dumb as a rock but started up a printing company from scratch and is very successful. He placed his shop where all of the "smart" people said it would not succeed but it did. He hired a very good manager whom he paid well. His business has flourished for 20 years now. A low IQ did not hurt him at all.

I have also seen very smart people piss their IQ's away. They graduated high school and goofed around and never applied themselves to anything and are out their flipping burgers for living. Not that there is anything wrong with flipping burgers, someone's gotta do it. However, all of their huge IQ did not help them at all.

I saw a poster in a classroom once that summed it up for me, it said "Your I Will Is More Important Than Your IQ".



I'd always suspected that the twin studies used to draw conclusions about IQ and heredity had a problem. In an evironment that allows for the full development of genetic potential, much of the differences in IQ can be ascribed to genes. But in the cases where the environment is inadequate, this does not necessarily apply. I've had exchanges with Charles Murray and other 'IQ and genetics' guys over this. They dismiss the point by saying that only in cases of extreme deprivation and abuse does the environment have such a significant impact.

This work by Eric Turkheimer, described by David Kirp, suggests we need a more subtle approach to studying the nature-nurture issue.


Turkheimer, a psychology professor at the University of Virginia, is the kind of irreverent academic who gives his papers user-friendly titles like “Spinach and Ice Cream” and “Mobiles.” He also has a reputation as a methodologist’s methodologist. In combing through the research, he noticed that the twins being studied had middle-class backgrounds. The explanation was simple — poor people don’t volunteer for research projects — but he wondered whether this omission mattered.

Full article (http://www.nytimes.com/2006/07/23/magazine/23wwln_idealab.html?pagewanted=1&_r=2&ei=5090)

Copyright (c) New York Times Magazine/David L. Kirp

[Ryokan]

I'd always suspected that the twin studies used to draw conclusions about IQ and heredity had a problem. In an evironment that allows for the full development of genetic potential, much of the differences in IQ can be ascribed to genes. But in the cases where the environment is inadequate, this does not necessarily apply. I've had exchanges with Charles Murray and other 'IQ and genetics' guys over this. They dismiss the point by saying that only in cases of extreme deprivation and abuse does the environment have such a significant impact.

This work by Eric Turkheimer, described by David Kirp, suggests we need a more subtle approach to studying the nature-nurture issue.


Turkheimer, a psychology professor at the University of Virginia, is the kind of irreverent academic who gives his papers user-friendly titles like “Spinach and Ice Cream” and “Mobiles.” He also has a reputation as a methodologist’s methodologist. In combing through the research, he noticed that the twins being studied had middle-class backgrounds. The explanation was simple — poor people don’t volunteer for research projects — but he wondered whether this omission mattered.

Full article (http://www.nytimes.com/2006/07/23/magazine/23wwln_idealab.html?pagewanted=1&_r=2&ei=5090)

Copyright (c) New York Times Magazine/David L. Kirp

Great article.

[Tladatsi]

After my initial post, I had a couple of additional thoughts, which ignore the question of whether IQ actually measures anything worth measuring,

1) Adopted twin studies are performed on infants, not older children, for pretty obvious reasons. Poor people don't generally adopt infant children, if they adopt any at all. Adoption of infants is an expensive process. Agencies look to place children in home that is best able to provide for the materials and emotional needs of the child. From the both agency and parent end, everything is set up to exclude poor people from adopting infants, including separated twins. So, separated twin infants are rarely, if ever, raise by poor people. Them volunteering is not even an option.

2) A well established predictor of childhood IQ is iodide in the maternal and child's diet. Iodide is needed for the production of thyroxine (T4) and Triiodothyronine (T3) where are critical for neuroskeletal development. A lack of sufficient iodide is well established to produce lower IQ scores in children, if not frank retardation. Poor people are more likely to have iodide deficient diets than other classes.

3) Maternal and childhood exposure to lead is another key predictor. Lead is a well known neurotoxin and inhibits normal brain development. In the 20th centrury the two major sources of lead exposure were automobile exhaust (tetra-ethyl lead, TEL) and leaded paints. So living in older housing (leaded paint was banned in 1978) and near major streets and highways was a predictor for serious lead exposure. You guessed it, poor people are more likely to have lived in those areas. Fortunately, TEL was banned almost 20 years ago, reducing the overall lead burden by 90%. Today, leaded pain in older houses is the only major source of childhood and maternal lead exposure.





I'd always suspected that the twin studies used to draw conclusions about IQ and heredity had a problem. In an evironment that allows for the full development of genetic potential, much of the differences in IQ can be ascribed to genes. But in the cases where the environment is inadequate, this does not necessarily apply. I've had exchanges with Charles Murray and other 'IQ and genetics' guys over this. They dismiss the point by saying that only in cases of extreme deprivation and abuse does the environment have such a significant impact.

This work by Eric Turkheimer, described by David Kirp, suggests we need a more subtle approach to studying the nature-nurture issue.


Turkheimer, a psychology professor at the University of Virginia, is the kind of irreverent academic who gives his papers user-friendly titles like “Spinach and Ice Cream” and “Mobiles.” He also has a reputation as a methodologist’s methodologist. In combing through the research, he noticed that the twins being studied had middle-class backgrounds. The explanation was simple — poor people don’t volunteer for research projects — but he wondered whether this omission mattered.

Full article (http://www.nytimes.com/2006/07/23/magazine/23wwln_idealab.html?pagewanted=1&_r=2&ei=5090)

Copyright (c) New York Times Magazine/David L. Kirp