People who don’t know much often think they know more than they know.

Misinformation can start when minimally informed people mistake associations with evidence of causation.

People exhibiting the Dunning-Kruger Effect often reject information that conflicts with their beliefs.

Cognitive dissonance can help unwind belief in misinformation.

In a class I recently taught about U.S. Health Care Policy & Politics, I asked the students how many health policy experts there are in the United States. Amidst a field of befuddled faces, one student said "300 million." That is basically the right answer because virtually everyone who has been ill or seen a clinician for a checkup or physical believes they understand the U.S. health care system’s problems and know how to fix them.[i]

This illustrates what is sometimes called the Dunning-Kruger Effect (DKE)[ii], in which, for example, someone with some knowledge of a subject believes they know more than people who’ve studied (or worked in) a field for many decades.

Drs. Dunning and Kruger

We are now in situation where health misinformation is being promoted by people who have significant public platforms for spreading fallacies, which could be dangerous to the health of individuals, communities, and countries. For example, during and since the COVID-19 pandemic, public figures have repeatedly asserted substantial knowledge and understanding of vaccines while criticizing many actual experts. This resulted in lower vaccine confidence and reinforced many people’s belief in misinformation. Interestingly, in the fall of 2025, many people who had (incorrectly) come to believe that vaccines were a primary cause of autism were confounded (if not distraught) when the U.S. government announced that acetaminophen was a cause of autism without also mentioning vaccines.[iii]

People exhibiting the Dunning-Kruger Effect also often do not understand (or appreciate, or recognize) the difference between associations (or correlations) and causations. An extreme example of that fallacy would be that using sunscreen causes shark attacks. (Both increase during warmer weather, but it does not mean that sunscreens attract sharks.) In contrast, an actual cause-and-effect relationship is that........

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