Are stupid people more likely to die from a heart attack?

ashtrays cause cancer? bad researchI’m still chewing on the extraordinary flame-out that is the medical research from the British Wellcome Trust and the Medical Research Council, as reported in BBC News under the headline Lower IQ ‘a heart disease risk’.

The problem? They have committed the cardinal research sin of taking correlational data and concluding causality. It’s a classic logic problem as illustrated by this: smokers have ashtrays in their houses. Smokers get lung cancer. Therefore ashtrays cause cancer.

Their research shows:

“when the researchers took into account IQ and controlled for nine other known heart disease risk factors, IQ alone explained 23% of the differences in mortality between the highest and lowest socioeconomic groups in the study.

Think about that. How can they really conclude what they’re presenting as research information?

Scientific research is predicated on the ability to remove variables from the equation so you can really see what causes what and what is correlated with what. Without a good research sense, you really might be confident that ash trays cause cancer.

Back to the research article…

“Professor Alan Maryon-Davis, president of the UK Faculty of Public Health, said: “People with lower IQ also tend to miss out on preventive healthcare.

“They are less likely to have check-ups, follow lifestyle advice, take preventive medication and be referred for preventive hospital treatment. We must find ways to break down these barriers.”

Again, these are correlational factors. They’re likely true, but to say that people with lower IQs are less likely to get medical care, therefore we can conclude that stupidity causes cancer.

I’m all for us trying to compensate for the ceaseless drumbeat of cheap, unhealthy food and lifestyle options, but let’s clean up the research so that when we make the case, we can actually have decent, measurable results.

4 comments on “Are stupid people more likely to die from a heart attack?

  1. As I read it they are not saying IQ causes heart disease, they are saying IQ explains higher mortality or how long one can live with heart disease. The premise as you pointed out is that if you don’t follow advice then the heart disease will claim you quicker.
    A similar analagy would be that I believe I can fly by flapping my arms. So I jump off a tall building and flap my arms. The direct cause of my death will be my impact with the ground. But one could back up to the “fall” as explaining why I died of impact. One could back up further and say it was my belief I could fly that ultimately explained why I died from an impact to the ground.

  2. Dave, I’ve got to say I’m not entirely sure what your problem with this article is. The researchers are quoted as saying that the study ‘raises the possibility’ that IQ may need to be considered as an explanation for why people in lower socioeconomic groups have higher cardiac mortality, and that there are ‘several possible explanations’ for their findings. That sounds entirely reasonable to me. I don’t see anywhere where they’re claiming to have concluded that low IQ definitely causes heart disease. What do you think is wrong with their research or the way it’s been presented here?

  3. The problem in my eyes, Sarah, isn’t so much the research or researchers, but the inevitability that research writeups that emphasize “the potential correlation between” becomes news stories about “A causes B”.

  4. That’s a problem, all right, and I quite agree with you there. But don’t blame the research or the researchers for the way the research gets presented. Hell, it’s the reverse of shooting the messenger. 😉

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