TCS Daily

Highballs and High IQs

By Dennis Mangan - May 9, 2005 12:00 AM

These days it is widely known that moderate consumption of alcohol has beneficial effects on health. Whether the drink is red wine, beer, or distilled spirits, the benefits are seen. The risk of dying in any given year is about 25% lower for moderate drinkers as compared to teetotalers. It's been estimated that coronary artery disease occurs at a rate in moderate consumers of alcohol only 40 to 60% of that seen in abstainers. Studies have shown a wide range of beneficial effects of drinking alcohol on conditions such as stroke, dementia, gallstones, and Parkinson's disease. Most drinkers have rightly seen all of this as very good news.

Alcohol has been shown to reduce blood levels of C-reactive protein, a marker for inflammation. It's been hypothesized over the past few years that inflammation is a key process in the development of many diseases, including heart disease, arthritis, cancer, stroke, and senile dementia. The moderate consumption of alcohol may likely exert its beneficial effects in part, at least, by its anti-inflammatory action.

But what if alcohol exerts its effects some other way? Or, more interestingly, what if alcohol did not even have beneficial effects in itself, but was, rather, correlated with some other factor seen among moderate consumers of alcohol?

One possible factor which, while possibly not entirely accounting for all of drinking's benefits, confounds the research into the healthy side of imbibing alcohol, concealing the main source of longevity and good health. What is that other factor? It is g, or general intelligence; it is what IQ tests measure.

Higher IQ has been shown to be positively correlated with longevity. People with greater intelligence suffer fewer accidents, commit suicide at lower rates, they have lower rates of heart disease, diabetes, lung disease, and hypertension. A study of Australian military veterans found that those with the lowest IQs were three times as likely to be dead of an auto accident at age 40 than those with the highest. Linda Gottfredson, a professor of psychology at the University of Delaware, has postulated that intelligence is "the elusive 'fundamental cause' of social class inequalities in health". That is, social class, income, and years of education are all highly correlated with general intelligence, and they are correlated with health as well.

Now, what do we see when we look at all those moderate drinkers? For one thing, they are more highly educated. According to one study, the percentage of college graduates who drank in the month previous to a survey was nearly 70%, while the same survey showed the rate of drinkers among those with less than a high school education to be under 40%. Those moderate drinkers also earn more; in one study, even when controlling for education, age, occupation, region, and health, abstainers had incomes on average 10% less than drinkers.

And all of those highly-educated, high income earning people are also more intelligent. They have better health, fewer accidents, and greater longevity. And they drink. Therefore, I would suggest that the higher IQs of all those drinkers is the "fundamental cause" of their better health; at a minimum, it is a confounding factor that needs to be controlled for in further studies on the beneficial effects on health of alcohol. Such studies could ascertain whether moderate drinking is indeed good for you, or whether all of those drinkers would have better health anyway, because of their higher general intelligence.

The author is a clinical lab scientist. Find more of his writing here.



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