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Extreme opponents of genetically modified foods know the least but think they know the most



There is widespread agreement among scientists that genetically modified foods are safe to consume1,2 and have the potential to provide substantial benefits to humankind3. However, many people still harbour concerns about them or oppose their use4,5. In a nationally representative sample of US adults, we find that as extremity of opposition to and concern about genetically modified foods increases, objective knowledge about science and genetics decreases, but perceived understanding of genetically modified foods increases. Extreme opponents know the least, but think they know the most. Moreover, the relationship between self-assessed and objective knowledge shifts from positive to negative at high levels of opposition. Similar results were obtained in a parallel study with representative samples from the United States, France and Germany, and in a study testing attitudes about a medical application of genetic engineering technology (gene therapy). This pattern did not emerge, however, for attitudes and beliefs about climate change.

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Fig. 1: Objective and self-assessed knowledge means by extremity of opposition.
Fig. 2: Predicted relationship between science literacy and self-assessed knowledge by extremity of opposition.
Fig. 3: Predicted relationships between extremity of opposition and knowledge by country.

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All data reported in the paper are available at


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This research was funded by a grant from Humility & Conviction in Public Life, a project of the University of Connecticut sponsored by the John Templeton Foundation to P.M.F., by the Center for Ethics and Social Responsibility at the University of Colorado, by a National Science Foundation DRMS grant (Award Number: 1559371) to S.E.S. and by an SSHRC grant (Award Number: 435-2017-0304) to Y.I. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. We thank B. de Langhe, D. Lichtenstein, J. Lynch, G. McClelland, L. Min, J. Pomerance, D. Rothschild, S. Shaw and S. Sloman.

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P.M.F. devised the paper’s central idea, and independently, as part of a larger study, S.E.S., Y.I. and P.R. considered the same idea. P.M.F. and N.L. developed the predictions and designed Studies 1, 3 and 4. N.L. performed the analyses and P.M.F. supervised the findings. For Study 2, S.E.S., Y.I. and P.R. developed the predictions and design and S.E.S. performed the analysis. P.M.F. and N.L. wrote the original manuscript and all authors contributed to the final manuscript.

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Correspondence to Philip M. Fernbach.

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Fernbach, P.M., Light, N., Scott, S.E. et al. Extreme opponents of genetically modified foods know the least but think they know the most. Nat Hum Behav 3, 251–256 (2019).

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