What do opponents of genetically modified foods really know about the science?

The study, published in Nature Human Behaviour, found that the strongest critics actually know less—a pattern similar for gene therapy, but not for climate change.

orange with GMO sticker sliced in half with different colored orange segments inside

People who hold the most extreme negative views about genetically modified (GM) foods think they know the most about GM food science, but they actually know the least, according to new research published in the journal Nature Human Behaviour. The work was a collaboration between Penn, the University of Colorado Boulder, Washington University in St. Louis, and the University of Toronto.

“It’s always interesting, and not infrequent, that people with particularly strong opinions about a subject are less informed about it than those in the middle of the spectrum,” says Paul Rozin, a professor in Penn’s Department of Psychology and an author on the paper. “People who fall more in the middle often more willingly consider positions alternative to their own.” 

For the research, more than 2,000 adults in the United States and Europe ranked their feelings about GM foods on a scale of 1 to 7, with 7 being the greatest apprehension. More than 90 percent reported some level of opposition or concern, despite a scientific consensus that GM foods—organisms modified to resist insects or pesticides—are safe for human consumption and have the potential to provide significant benefits. 

With the concern levels noted, the surveys then asked respondents how well they thought they understood genetically modified foods, and tested their actual knowledge with a battery of true-false questions on general science and genetics. The researchers found that the more strongly people stated their opposition to such foods, the more they thought they knew about the topic but the lower they scored on the test.

“This result is perverse but is consistent with previous research on the psychology of extremism,” says Philip Fernbach, the study’s lead author and an assistant professor of marketing at the University of Colorado Boulder. “Extreme views often stem from people feeling they understand complex topics better than they do.”

One potential consequence of this phenomenon is that the people who know the least about important scientific issues may be likely to stay that way because they may not seek out or be open to new knowledge. “Changing peoples’ minds first requires them to appreciate what they don’t know,” says study co-author Nicholas Light, a doctoral candidate at CU Boulder. “Without this first step, educational interventions might not work very well to bring people in line with the scientific consensus.”

The researchers also explored other issues like gene therapy and climate-change denial. Though they found the same results for the former—that extreme opponents were less knowledgeable yet thought they knew more—the pattern did not emerge for the latter. The climate-change debate has become so politically polarized, the researchers hypothesize, that people’s attitudes depend more on which political group they affiliate with than how much they know about the issue. 

Future research will analyze similar knowledge and thought processes related to issues like vaccinations, nuclear power, and homeopathic medicine.

This research was funded by the National Science Foundation (Grant 1559371), Social Sciences and Humanities Research Council (Grant 435-2017-0304), Humility & Conviction in Public Life project at the University of Connecticut, and Center for Ethics and Social Responsibility at CU Boulder.

Paul Rozin is a professor in the Department of Psychology in the School of Arts and Sciences at the University of Pennsylvania

Philip Fernbach is an assistant professor of marketing at the Leeds School of Business at the University of Colorado Boulder

Nicholas Light is a marketing doctoral candidate at the Leeds School of Business at the University of Colorado Boulder