Analysis of surveys from US, France and Germany could also have implications for science communication in other fields

The most extreme opponents of genetically modified foods know the least about science but believe they know the most, researchers have found.

The findings from public surveys in the US, France and Germany suggest that rather than being a barrier to the possession of strongly held views, ignorance of the matter at hand might better be described as a fuel.

“This is part and parcel of the psychology of extremism,” said Philip Fernbach, a researcher at the University of Colorado and co-author of the 2017 book The Knowledge Illusion. “To maintain these strong counter-scientific consensus views, you kind of have to have a lack of knowledge.”

Fernbach and others analysed surveys completed by nationally representative samples of the US, French and German public. Those who took part were asked about their attitudes to GM foods and given instructions on how to judge their understanding of the topic. Next, they completed a scientific literacy test. Among the statements the participants had to wrestle with were: “Ordinary tomatoes do not have genes, whereas genetically modified tomatoes do” (false), and “the oxygen we breathe comes from plants” (true).

The results from more than 2,500 respondents revealed the curious trend. “What we found is that as the extremity of opposition increased, objective knowledge went down, but self-assessed knowledge went up,” Fernbach said.

“The extremists are more poorly calibrated. If you don’t know much, it’s hard to assess how much you know,” Fernbach added. “The feeling of understanding that they have then stops them from learning the truth. Extremism can be perverse in that way.”

The finding has echoes of the Dunning-Kruger effect, the observation from social psychology that incompetence prevents the incompetent from recognising their incompetence. A case in point is the bank robber who was baffled to be caught after rubbing lemon juice into his face in the belief it would make him invisible to security cameras.

Fernbach believes that his findings, reported in Nature Human Behaviour, could have major implications for science and policy communication. One long-held, but rather unsuccessful, belief in the field of communications is that better education is the way to counter anti-scientific attitudes.

“Our research shows that you need to add something else to the equation,” Fernbach said. “Extremists think they understand this stuff already, so they are not going to be very receptive to education. You first need to get them to appreciate the gaps in their knowledge.”

Graham O’Dwyer, a politics lecturer at Reading University with a specific interest in human irrationality, welcomed the study. “It carries a clear argument that is very convincing, and it also feeds into a wider set of concerns in relation to ignorance, overconfidence, and erroneous views in our present times.”

Beyond parallels with the Dunning-Kruger effect, O’Dwyer said two other cognitive biases may feed into the trend Fernbach observed. The first is “active information avoidance”, where people reject information that would help them understand the world because it clashes with their existing beliefs. The second is the “backfire effect”, which describes how people can become entrenched in their original positions after rejecting new information.

“This is often used to explain why many Americans refuse to believe in evolution and why so many Americans feel that vaccination is harmful to children,” O’Dwyer said. “It also figures into the debates on global warming and makes correcting erroneous beliefs highly challenging.”