Intelligence and Health

“Intelligence predicts health and longevity, but why?”, ask Linda Gottfredson and Ian Deary in Current Directions in Psychological Science (here is the pdf). Mathilda at her anthropology blog quotes some highlights from the paper:

a drop of 1 standard deviation in IQ was associated with a 27% increase in cancer deaths among men and a 40% increase in cancer deaths among women….

For each standard deviation increase in IQ, there was a 33% increased rate of quitting smoking. Adjusting for social class reduced this rate only mildly, to 25%. Thus, childhood IQ was not associated with starting smoking (mostly in the 1930s, when the public were not aware of health risks), but was associated with giving up smoking as health risks became evident.

When all other variables were statistically controlled, each additional IQ point predicted a 1% decrease in risk of death. Also, IQ was the best predictor of the major cause of death, motor vehicle accidents. Vehicular death rates doubled and then tripled at successively lower IQ ranges (100-115, 85-100, 80-85).

In this connection, it would be interesting to see a graph comparing the increase of the Hispanic percentage of the population of California over the last fifty years with the California’s rate of vehicular death. Imagine that, the next time Congress debates legalizing illegal aliens and increasing Hispanic and Third-World immigration, some congessman has the temerity to say: “Hispanic IQ is ten points lower than the white American IQ. For every increase in our Hispanic population, this country will have more vehicular deaths, more health problems, and more health care costs.” And imagine that, when this congressman is shouted down and called a racist, other congressmen, media, and scientists come to his support and show that his facts are correct.

Hey, I can dream, can’t I?

- end of initial entry -

Doug J. writes:

I read your site every day, and I consider it to be highly valuable. However, I do have to disagree with you about the Mexican IQ. You have stated at least twice that it is 10 points lower than the average white IQ. I honestly believe this is in error. According to all of the information that I can find, if you would average the high side and the low side, the Mexican IQ is 88. This is in Mexico, which has a 9 percent white population. The illegal Mexicans we get in this country are almost all non white. I have read articles that their average IQ is actually below the American Negro. I do not know if this is accurate, but I have a hard time believing that the average IQ of the illegals is as high as the average Mexican IQ. Therefore, I believe you should make some adjustments on the 10 point difference between the average illegal IQ and the native white population IQ.

Posted by Lawrence Auster at June 08, 2010 02:35 PM | Send