By Brian Carnell

Sunday, July 18, 2004

Frankly, I have no idea whether smarter people really live longer than stupid people on average, but Z Magazine writer Yves Engler puts herself squarely on the latter end of the spectrum with her effort to debunk the claim.

Her first couple paragraphs shows a woeful ignorance of the claim being made about correlations between IQ and health outcomes. Engler writes,

U.S. residents are dumber than people living in every other industrialized nation.

That conclusion doesn't come from some left-wing Frenchman or Russia commie or pinko Canadian -- it is the logical inference of a recent Forbes magazine article. In "Why the Rich Live Longer" Dan Seligman provides a "stunning new explanation for upscale longevity;" wealthier people live longer because they have higher IQs -- this according to research by a U.S. sociologist and British psychologist summarized by Seligman for Forbes' (well-to-do) readers.

In fact the claim that Americans are dumber than other people in industrialized nations is a stupid claim that comes only from Engler herself. As Seligman notes in the second paragraph of his article,

One of the great mysteries of modern medicine: Why do rich people live longer than poor people? Why is it that, all around the world, those with more income, education and high-status jobs score higher on various measures of health? As stated in a World Health Organization pamphlet: "People further down the social ladder usually run at least twice the risk of serious illness and premature death of those near the top."

The question, then is why in any given country are those at the top of the social ladder living longer than those at the bottom, not why people in one country live longer that those in another. Assume for the moment that the IQ hypothesis is correct -- that the smarter people are, on average, the longer they live. This would mean, then, that the smarter people in, say, Sudan, should live significantly longer than people with low IQs in that country. It does not follow logically at all, despite Engler's claims otherwise, that the Sudanese intellectual elite is significantly dumber than their American counterparts, simply because Americans with high IQ live even longer than Sudanese with high IQs.

Engler also conveniently forgets to point out that the difference in life expectancy between industrial countries is very small. The United States in 2000, for example, had a life expectancy at birth of 77.2 years. Excluding the microstates of Andorra and San Marino, Japan led the world that year with a life expectancy of 80.7 years. A 3.5 year difference given the United States' multicultural makeup and allowing for the years lost due to the way infant mortality is calculated in the United States, that's an extremely small difference.

Selig's article is filled with a lot of interesting tidbits, but suffers from equating IQ with status. For example, he cites a 1994 study of British civil servants that found those at the highest status levels outlived those at lower status levels, even though they were working in similar environments and had similar levels of access to health care. But the study apparently didn't examine how well IQ differences correlated with status differences.

Similarly, Selig cites studies showing that relatively high percentages of Americans have difficulty understanding basic health concepts -- such as studies showing that as many as 50 percent of all prescriptions are taken incorrectly -- but again, there's not a whole lot of direct information there correlating IQ, rather than status, with ability to follow a doctor's directions.

Certainly there is likely to be some difference based on IQ, but Selig ignores alternative explanations, such as the difficulties in crafting strategies that work equally effectively across America's many cultural groups (the same anti-AIDS program that works wonders for suburban-dwelling whites is likely not going to work nearly as well for urban-dwelling blacks). Unfortunately, Selig doesn't offer chronic disease breakdowns by race so readers can compare those with his breakdown by status (it would be interesting, for example, to see a comparison of chronic diseases afflicting blacks vs. whites with bachelor's degrees rather than simply a comparison of bachelor's to high school graduates and those with some college as Selig provides.)

Most of Engler's direct criticism of Selig's version of the IQ hypothesis, however, result on goofy claims such as this about why Japanese men have so little case of lung cancer as compared to American men, even though they smoke roughly the same amount,

Seligman’s second objection is “the notoriously high rate of smoking in the low-status population.” While smoking is a major health hazard – more severe than had been accepted as the U.S. Surgeon General recently pointed out — it does not adequately explain the health gap between poorer and wealthier people. As Dr. Stephen Bezruchka from the University of Washington explains: "Japanese men smoke the most of all rich countries. Yet they are the healthiest population on the planet. It seems you can smoke in Japan and get away with it. It’s not that smoking is good for you, but that compared to other things, it isn’t that bad. Smoking is much worse for you in the U.S. than it is for the Japanese in Japan, where the gap between the rich and poor is much less… Similarly, it isn’t Japan’s health care system that is responsible for its remarkable health. Anyone who has looked at their system will tell you it isn’t much to write home about…Japan is a caring and sharing society that looks after everyone and that matters most for your health."

That explanation is just plain goofy. That cancer attributed to exposure to particulate matter would be ameliorated by being part of a more "caring and sharing society" is simply absurd. The reader is also left to wonder how Engler and Bezruchka explain "caring and sharing" Japan's world leading rate of suicide. Do people in Japan kill themselves so frequently because they care too much?

This explanation also doesn't explain why Japanese smokers have significantly less relative risk of lung cancer compared to European men. Is Europe just as cold and uncaring as the United States?

Of course, the likely explanation for the difference has nothing to do with caring or sharing. Rather it is likely due to two factors: a) the sort of cigarettes Japanese men smoke, and b) the sort of diet Japanese men eat.

First, Japanese men smoke cigarettes that are, on average, likely less damaging to their lungs. Cigarettes sold in the United States tend to have much higher concentrations of toxins, and U.S. men are fare less likely to smoke cigarettes with activated charcoal filters than are men in Japan.

Second, Japanese men eat a diet which is hypothesizes to provide much greater cancer fighting properties than American men. The relatively high consumption of fresh fish has frequently been cited as one possibility, and studies of cancer in Japanese men and women have found that those who eat the most fresh fish had relative risks for some forms of cancer that were only half as high as those who ate the least fresh fish.

Sources:

Status, Health And Stupidity. Yves Engler, Z Magazine, July 11, 2004.

Smoking and lung cancer risk in American and Japanese men: an international case-control study. Stellman SD, et al. Cancer Epidemiol Biomarkers Prev. 2001 Nov; 10(11):1193-9.

Cigarette smoking and subsequent risk of lung cancer by histologic type in middle-aged Japanese men and women: the JPHC study. Sobute T, et al, Int J Cancer. 2002 May 10;99(2):245-51.

Sushi may protect against rare type of lung cancer. Richard Woodman, Reuters Health, May 3, 2001.

Why the Rich Live Longer. Dan Seligman, Forbes, July 7, 2004.

Discuss (6 Replies) | Printer Friendly