Cain and Abel

Is Ad Hominem Logic Creeping into Scholarly Discourse?

Ad hominem logic seem to be ruling the day. International diplomacy features name calling between a little rocket man and a dotard. And now, people are starting to call for the dotard to receive a Nobel Peace Prize. So is it really surprising to see ad hominem logic creeping into scholarly discourse?

Ad Hominem Logic Persuades the Public

A recent study in PLOS One suggests that ad hominem logic works. At least it works with the public. In a pair of experiments, Ralph Barnes and colleagues studied the effects of ad hominem arguments about conflicts of interest. They showed that such arguments do a fine job of undermining the credibility of scientific research.

In fact, ad hominems were every bit as effective as pointing out real, factual errors. Likewise, evidence of outright fraud was no more damning than the mere suggestion of a conflict of interest.

Advancing Ad Hominem Logic

Look around and you can see ad hominems cropping up, especially in nutrition science. Scientists now question the merits of each other’s work on Twitter in rather personal terms. Tweetorials offer scathing critiques of nutrition research. A journal paper uses quotes from a single email exchange to advance theories about food industry conspiracies. This sparks accusations that conspiracy theories are masquerading as academic scholarship.

It all gets ugly and counterproductive very fast.

Staying True to Science

We are paying a price for ad hominem logic. Barnes notes that 91% of anti-vaccine websites explicitly call out conflicts of interest in biomedical research. Thus, say the anti-vaccine activists, science is unreliable. Nasty arguments about nutrition research set up similar credibility issues and confusion. Charlatans see an opening and they exploit it. Snake oil, juice cleanses, and wacky diets gain equal footing with science-based obesity care.

In fact, we need disciplined discourse about scientific rigor. Errors occur. People overlook statistical flaws and problems with methods sometimes. Peer review doesn’t catch every error. Finding scientific truth comes from the process, not from a single flash of brilliance. But discourse that strays from the facts and into the ad hominem simply gets in the way. It undermines everyone’s credibility, and ultimately, the public’s trust in science.

That price is too steep.

Click here for the study by Barnes et al and here for a perspective on the quality of scientific discourse.

Cain and Abel, painting by Titian / WikiArt

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May 13, 2018