Spurious Correlation: Obesity and Criminality

Physiognomy – a textbook example of pseudoscience – came from ancient Greeks and fell into disrepute during the Middle Ages. This is the practice of judging a person’s character by their physical appearance. It happens, of course. But we’re more than surprised to find a medical journal – Sage Open Medicine – giving it credence. A new analysis in the journal by Adam Powell and colleagues finds a spurious correlation between criminality in a pediatric obesity clinic population by comparison with normative data.

So they conclude that “pediatric youth who have obesity have high rates of criminal behavior” and thus need “increased surveillance for risk-taking behaviors.”

Translated into common parlance, the researchers are essentially saying: Keep an eye on kids with obesity. They might turn into criminals.

Relying on a Convenience Sample

To reach this conclusion, the researchers started with a convenience sample – 716 patients from a weight management clinic at Cincinnati Children’s Hospital between 2009 and 2019. We give the authors credit for a bit of introspection about this flaw in their methods. In a masterstroke of understatement, they write:

“The pediatric patients recruited from the HealthWorks! clinic may not be representative of the comparison group of Midwest adults. There may be confounding factors not evaluated which could, in turn, explain these differences, such as income disparities, educational level, and living in underfunded areas.”

Yes. Social and economic factors are indeed important. So we wonder why these authors did not analyze these factors in their population. The lack of any accounting for the inherently unusual nature of their sample population renders their study meaningless.

So no. Their analysis does not provide evidence that obesity puts kids at risk for criminal behavior. This unfounded suggestion is offensive. It reminds us of another paper – now retracted – with dubious methods that tried to link obesity to dishonesty.

Promoting Weight Stigma Is Unethical

Beyond the offensiveness of the unfounded generalization about kids with obesity, there is the ethical problem of promoting weight stigma in a medical journal. At this point, there’s really no room for debate about the harm that weight stigma does to kids. The authors of this study would do well to study the policy statement of the American Academy of Pediatrics on weight stigma and the harm it causes.

Because they make no mention of stigma or bias whatsoever in their publication, we suspect that it may never have occurred to the authors that they are promoting weight stigma, rather than publishing meaningful research.

So in the end, we can find no merit in this paper. Only a spurious correlation with obesity that doesn’t stand up to scrutiny but does promote weight stigma. Given the harm that weight stigma does to children, we have serious ethical concerns with its publication in a medical journal.

Click here for the paper by Powell et al. For further perspective, click here and here.

Criminal Physiognomies, pastel by Edgar Degas / WikiArt

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November 9, 2022