How is Scientific Credibility Affected by Communicating Uncertainty? The Case of Endocrine Disrupter Effects on Male Fertility

ABSTRACT

Using the case of endocrine disrupter effects on male fertility, we explored how communicating uncertainty influences the credibility of the information that laypeople receive from scientists and how laypeople form judgments about the relationship between uncertainty and credibility. We found that laypeople assess the credibility of scientific information—whether or not it is accompanied by uncertainty—by referencing their “science model” and using non-scientific references (i.e., situations encountered in one's daily life, information received from other sources, one's own observations of the world, and one's education or professional experience). Scientific credibility is a mixture of (sometimes contradictory) considerations along these different axes. Previous studies have found that some scientists assume that communicating uncertainty will lower public credibility of science. Our results contradict this assumption for situations in which academic scientists communicate uncertainty, which is perceived as additional knowledge bringing a new perspective on certain information. People expect scientists to provide practical solutions and feel disillusionment when scientists lack straight answers. However, they accepted uncertainty as an intrinsic characteristic of science and a consequence of the limits to human beings’ capacity to understand the world. Further, the low credibility of industry scientists is further reinforced when they communicate uncertainty.

Key Words:

• endocrine disrupter
• controversy
• uncertainty
• risk communication
• credibility
• trust

ACKNOWLEDGMENTS

This work has been funded by the Interdisciplinary Programme “Communication Sciences” of the National Center for Scientific Research (CNRS), and within the framework of the PRO-MALE project. We are profoundly indebted to Bernard Jégou and Stéphane Bouchonnet for their contributions to our project, to Valérie Schafer, Mélanie Dulong-Desronay, Gaelle Lejeune, Charlotte Rouchon, and Marie-Laure Hustache for their help with the recruitment, to Isabelle Veyrat-Masson, Laurence Brunet, Stéphane Hugon, Laïla Idtaleb, to Claire Sécail for methodological advice, and to the anonymous reviewers for their comments. All our gratitude goes to Antoine Borderie, Pascal Dayez-Burgeon, Isabelle Meslet-Dina, and Christophe Potier-Thomas, without whose administrative support this project could not have been done, and to Sharilynn Wardrop for stylistic and linguistic improvements.

Notes

Uncertainty has been distinguished from risk since Keynes (1921) and Knight (1921). Whereas risk can be expressed through probabilities, for uncertainty “there is no scientific basis on which to form any calculable probability whatever. We simply do not know” (Keynes 1937, p 215).

For an excellent analysis of the early history of the controversy, see Krimsky (2000).

We have considered the income greater than 2000 Euros per household as being “high” and below this amount as being “low.”

The Eurobarometer report “Scientific research in the medias” (2007) has shown that most people in the European Union get their scientific information from television.

Acronym for Registration, Evaluation, and Authorization of Chemicals. REACH is a European Regulation that became effective in 2007, and that has three goals: (1) improving knowledge of the properties and uses of individual chemical substances, (2) increasing the speed and efficiency of the risk assessment process, and (3) making producers and importers responsible for this process.