Thursday, April 16, 2009

Kristof vs. Reality

So today in the New York Times there is an editorial by Nick Kristof on the role of intelligence. He basically tries to shoot down the notion that intelligence in inherited. Here are some of his arguments:

One gauge of that is that when poor children are adopted into upper-middle-class households, their I.Q.’s rise by 12 to 18 points, depending on the study. For example, a French study showed that children from poor households adopted into upper-middle-class homes averaged an I.Q. of 107 by one test and 111 by another. Their siblings who were not adopted averaged 95 on both tests.

Indeed, the average I.Q. of a person in 1917 would amount to only 73 on today’s I.Q. test. Half the population of 1917 would be considered mentally retarded by today’s measurements, Professor Nisbett says.

Flynn Effect

Another proven intervention is to tell junior-high-school students that I.Q. is expandable, and that their intelligence is something they can help shape. Students exposed to that idea work harder and get better grades.

He has some interesting points. However, the report entitled Intelligence: Knowns and Unknowns showcases a basic fact:

"Recent twin and adoption studies suggest that while the effect of the family environment is substantial in early childhood, it becomes quite small by late adolescence. These findings suggest that differences in the life styles of families whatever their importance may be for many aspects of children's lives make little long-term difference for the skills measured by intelligence tests."

So we can dispute statistics and tests. Every liberal commentator can easily cherry pick a few tests that show that in certain circumstance, stupid people will do better than usual with certain environments. But he never addressed the deep structural contradictions with claiming that everyone has equal IQ. On the surface, you know that's absurd-families raising non-twin siblings easily see the differences in intelligence between them.

What they key is, is that brain structure matters. It's what makes humans more intelligent than animals, and it gives us our own personalities

The researchers said the brain differences are structural and can be measured as variations in the size of specific regions of the brain that appear to be linked with each of the four personality types.

And even just a few years ago the NY Times reported that intelligence was genetic.

The researchers found that average children (I.Q. scores 83 to 108) reached a peak of cortical thickness at age 7 or 8. Highly intelligent children (121 to 149 in I.Q.) reached a peak thickness much later, at 13, followed by a more dynamic pruning process.

One interpretation, Dr. Rapoport said, is that the brains of highly intelligent children are more plastic or changeable, swinging through a higher trajectory of cortical thickening and thinning than occurs in average children. The scans show the "sculpturing or fine tuning of parts of the cortex which support higher level thought, and maybe this is happening more efficiently in the most intelligent children," Dr. Shaw said.

So Part I addressed why the basic science of Kristof is wrong. Part II will address the implications.

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