Archive for the 'Jim Manzi' Category

Jim Manzi answers one question on DNA and race

May 28, 2008

Old Atlantic:

You ask: “James Watson said or is thought to have said that the frequency distribution of IQ among blacks is lower than whites and this is at least partly genetic. Whether he said that or not, do you agree with it?

There are sustained, statistically significant differences in IQ-test performance between self-identified racial groups in the U.S., and these self-identified racial groups also have statistically significant differences in genetic content. It has not been demonstrated that these genetic differences cause the differences in test performance. I go into enormous detail supporting this assertion here:

Posted by Jim Manzi on May 27, 2008.


Mr. Manzi,

Thanks for answering one of my questions and directing me to your site.

I typed IQ genes into Google and
hit number 2 is

CHRM2 is the gene

“”If we look at a single marker, a DNA variation might influence IQ scores between two and four points, depending on which variant a person carries,” Dick said. “We did that all up and down the gene and found that the variations had cumulative effects, so that if one person had all of the ‘good’ variations and another all of the ‘bad’ variations, the difference in IQ might be 15 to 20 points.”

You can search on CHRM2 IQ race

The above link has a table on
racial differences and IQ gene DTNBP1.

“DTNBP1 explains 1/3 of the black-white IQ gap.”

You also didn’t answer my question on whether every species has to produce extra copies of good genes each generation and fewer of bad genes. And are humans doing the reverse now? Are humans in a genetic liquidity trap? How can CHRM2 and DTNBP1 variants good for IQ be spread if fewer than 2 copies are made each generation by high IQ parents?

==Other links

Has some on CHRM2 at above link.

Search iq genes

Search CHRM2 IQ race


Many scientific papers on these topics at

White women are most likely to be married among women of all races:


List and Links

NOT SO. I can name a couple of genes and not much more that influence intelligence:

Human neuropsin
and a small amount of genes on chromosome 4



Some comments on Jim Manzi’s article at above link. This is well written and thought out. However, we can measure IQ racial differences at the top of the column easily. Very few blacks produce great math. One exception is David Blackwell and there are others.

To tell if two bodies of water are the same height you look at the top. Same with trees, people, etc. You don’t have to know the chemistry of the insides of the lakes, trees, or people to tell that one is higher than the other. Its the same with intelligence. We look at the top of the races and see a huge difference. That is the measurement. We can look at the societies and civilizations and see a large part of the distribution.

If blacks can’t figure out not to eat lead, that is an indication of intelligence. Whites did figure that one out. Claiming its lead or whatever in the environment doesn’t explain why one group can figure out lead is a problem and avoid it. If lead was the problem, then liberals say its whites fault for not keeping blacks from ingesting lead.,0,6600780.story

Lead exposure in children linked to violent crime
A study finds that even low levels can permanently damage the brain. The research also shows that exposure is a continuing problem despite efforts to minimize it.
By Thomas H. Maugh II and Marla Cone, Los Angeles Times Staff Writers
May 28, 2008

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