Atlas: What are Dunning-Kruger effects?

Matthew Motta: A Dunning-Kruger effect generally refers to observable manifestations of what psychologists call “meta-ignorance.” It’s any of a host of behavioral consequences of people’s ignorance of their own ignorance. It’s what happens when people don’t know the lack of knowledge they have in a particular area. We were interested in studying the application of these effects in public health. We thought there were people who think they know more than medical experts and scientists who actually know quite a bit less. This would be an example of Dunning-Kruger effect because people don’t know how little they know in relation to people who know comparatively more.

Atlas: How is it that people who actually know less find it easier to believe they in fact know more than the experts?

Matthew Motta: There’s a couple ways this can happen. There are two things that go into whether someone exhibits Dunning-Kruger effects. One is having low knowledge and the other is being misinformed. Misinformation doesn’t imply that someone doesn’t know, but rather that they believe information that’s not true.

Atlas: What led you to explore these effects in relation to skepticism around vaccines and ideas about vaccines and autism (that persist despite I should say medical and scientific consensus to the contrary)?

Matthew Motta: There are a couple of reasons why we are interested in studying this. The academic answer is this is something psychologists have asked us to draw attention to for a long time. But really we’re interested in understanding why it is people don’t think vaccines are safe and what political and policy consequences that might have. Attitudes about vaccines can and do have very real public policy and health policy consequences. One example is the Lyme disease vaccine. In the late nineties there was a vaccine for Lyme disease, which public opinion helped pull off the market. The public was skeptical about the safety and effectiveness. Twenty years later, we finally have another vaccine [in clinical trial], but that took a long time. Understanding why the public rejects scientific consensus on things like vaccines and vaccine safety is a tremendously important question.

Atlas: How did you go about exploring this?

Matthew Motta: We gave people a knowledge test about the causes of autism and then we asked people in a national survey: How much do you think you know about the causes of autism? We asked the same question about medical experts like doctors and scientists. We compared people’s perceptions of self to perceptions of experts and looked at that versus how well they scored on the knowledge test. We show there’s a relationship between knowledge and misinformation and what we call overconfidence—the belief that you know more. As we showed, those who are the least knowledgeable and most misinformed were most likely to exhibit overconfidence. Once we did that, we looked at policy implications of overconfidence. We looked at the correlation between attitudes, for example, about whether it should be required to vaccinate kids going to public school. Those who were the most overconfident were less likely to think that was the case.

Atlas: What does this tell us?

Matthew Motta: If we understand where anti-consensus and skepticism comes from, it can help us better alleviate skepticism. We’ll know how to fix it or at least where to look. It’s tempting to think the answer is simple. We just need to educate people. If only people were more educated and less misinformed about autism, they would be less likely overconfident and more willing to support expert opinion. But, it’s not that simple. Informing the public is a monumental task, but knowledge isn’t a panacea. We know from other fields that sometimes those more knowledgeable have stronger cognitive biases. Even though knowledge is a potential path to explore, it’s important to keep in mind that knowledge won’t fix all of our problems.

Atlas: Do you have ideas about other ways to help?

Matthew Motta: Absolutely. A really important path is combatting misinformation about vaccines. Of course, we need efforts to inform people, but we also need to debunk misinformation. Hitting people over the head with facts probably isn’t going to do that. What it might look like is the subject of follow-up studies. That’s the key question: how can we combat misinformation about vaccines?

Atlas: Do your findings suggest that non-experts might actually reach people with doubts about vaccines more effectively than experts can? I’m thinking if some folks prefer to listen to celebrities, why would they not listen to celebrities who support vaccines as well?

Matthew Motta: That is one fascinating path to explore. We recognize that getting some of these folks like celebrities involved and perhaps family and friends might be a effective route because those with high levels of overconfidence tend to trust these non-experts on vaccines. If we can get celebrities or maybe family and friends to communicate support we might have effective way to combat misinformation. But there’s a huge “if” there—you need someone to change his or her mind. What that might look like in practice is hard to say but it could be a fascinating route to explore.

Atlas: Your work here is focused on anti-vaccine attitudes but it would seem to apply to many other areas of science and medicine as well, wouldn’t it?

Matthew Motta: Absolutely. There ought to be more studies on this than there are. We see this as one application and welcome people to look in other areas. We’ve considered looking at climate denial, but really anywhere expert and public opinion doesn’t match up is a great place to look.