What makes science trustworthy? A guide for the public


 The following article is authored by Heather Douglas.


  • The trustworthiness of science should not require scientific expertise to assess.
  • Trustworthiness should be based on the presence of expertise, good expert community functioning, and shared values.
  • This basis for trustworthiness is usable by the public, and does not require expert consensus, while capturing the value of consensus.
  • To foster trust with the public, scientists should 1) ensure their expert communities foster debate among diverse participants and from diverse perspectives and 2) share the value commitments that shape their science.

Why should the public trust science? The instrumental successes science has facilitated (e.g., eliminating smallpox, airplanes, the internet, etc.) provide one possible answer, but this does not consider past instrumental failures, where the promises of science have failed to deliver or brought unwelcome effects with them (e.g., failures to handle nuclear waste (Jacoby, 2020), worldwide contamination from plastics (Ritchie and Roser, 2022), localised and intractable chemical contamination (Environmental Working Group, 2022), etc.).


Others have argued that consensus among experts is a key metric for trustworthiness. However, scientists have settled on consensus views that have been wrong in the past (e.g., erroneous claims about racial hierarchies, faulty understandings of diseases such as the causes of ulcers). Sophisticated views on the trustworthiness of consensus have emphasised the need for consensus to be properly formed after sufficiently robust debate among a diverse group of experts (Anderson, 2012; Oreskes, 2019). Not just any consensus will do.


But this puts a great deal of pressure on consensus. Properly formed consensus can take a long time to coalesce, particularly if debate is sufficiently robust. What is the public to do in the meantime, before consensus has emerged? Further, this incentivises the prevention of consensus, often by disingenuous means, by those whose interests would be harmed by an emerging consensus. For example, fossil fuel interests founded fake academic journals and poured money into climate denial think tanks in order to give the appearance that consensus on the causes of climate change had not yet been reached (Oreskes and Conway, 2010). Years of delay resulted.


What is needed is an account of trust in science that enables the public to assess current science for trustworthiness, does not need to wait for a consensus to emerge, and can actually be utilised by a non-expert public. There are three bases central to assessing scientific expertise for trustworthiness: 1) the presence of expertise, 2) the engagement of the expert in a well-functioning expert community and 3) the sharing of values with the public


The presence of expertise can be assessed through either past successes of the expert, because they have made a series of good judgment calls in their area of expertise that have proven correct, or through their explanations of their judgments as experts. The latter route is particularly important in cases where the success of expert judgments cannot be readily assessed because of the timeframes or complexity of systems involved.  If one cannot assess the success of an expert directly, does the expert provide an account for why they think what they think? While degrees and awards can also help, they are not necessary.


What is necessary is that the expert be engaged in a community of experts, continually debating and refining their expertise. It is only in concert with other expertise that reliable judgments get honed. Assessing the community of experts can be challenging for the public, but aspects to look for are forums for debating views (e.g., conferences and journals) and an openness to the involvement of experts from a wide range of backgrounds. Expert communities that exclude others because of gender, ethnicity or class should be viewed as less trustworthy.


Finally, it is important that experts share values with members of the public, particularly social and ethical values. This is because experts need to frame their research problems in ways that capture the concerns of the public (e.g., not just treatments of diseases, but also risks of those treatments). Experts should share some of the values of the public in how they choose to define and pursue their research. In addition, experts need to assess when the evidence is sufficiently strong to support a scientific claim, and such judgments of evidential sufficiency need to weigh the risks any errors of judgment pose to the public – which requires social and ethical values.  Part of expert judgment is that the available evidence is strong enough—or not—to support scientific statements.  Risks of accepting a statement too soon, or waiting too long, include risks to the public.  Social and ethical values are thus central to the practice of expertise, even if they do not – and should not – determine the results of scientific inquiry. (Douglas, 2017; 2021)


A trustworthy scientific expert is thus someone who fulfils the above criteria, even when consensus has not yet formed among scientists. When debate is ongoing, members of the public can place trust in such an expert. The expert would make judgments about the science the way a member of the public would if they had the necessary expertise.


This view of what grounds the trustworthiness of scientific expertise for the public encompasses cases of consensus. When we have a properly formed scientific consensus, it will be produced by genuine experts engaged with a diverse and well-functioning expert community and at least some of those experts who share the consensus view will share the requisite public values.  The public can presume that there are at least some experts who participated in the consensus formation, who raised important issues in the debate leading to consensus, and who would make crucial judgments as they would if they had the needed expertise.  This makes the consensus trustworthy.


What does this mean for scientists? First, scientists should build a welcoming expert community that brings in the needed diversity of backgrounds. Second, scientists should ensure openness about ongoing debates and expert discussions, showing that the scientific community functions as it should. Third, when social and ethical values frame the problems scientists address and the judgments about evidential sufficiency for scientific claims, scientists should ensure that their values overlap with those of the public. Doing so will foster trust in science (Hicks and Lobato, 2022).


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Anderson, E. 2012, ‘Democracy, Public Policy, and Lay Assessments of Scientific Testimony’, vol. 8, no. 2, pp. 144-164, DOI:10.3366/epi.2011.0013.


Douglas, H. 2017, Science, values, and citizens. In Eppur si muove: Doing history and philosophy of science with Peter Machamer (pp. 83-96). Springer, Cham.


Douglas, H. 2021, The Rightful Place of Science: Science, Values, and Democracy. Consortium for Science, Policy & Outcomes, Tempe, Arizona.


Environmental Working Group 2022, PFAS Contamination in the U.S. (June 8, 2022), Environmental Working Group, viewed 12 December 2022, <https://www.ewg.org/interactive-maps/pfas_contamination/>


Hicks, D.J. and Lobato, E.J.C. 2022, ‘Values disclosures and trust in science: A replication study’’ Frontiers in  Communication,  vol. 7, no. 1017362, DOI: 10.3389/fcomm.2022.1017362.


Jacoby, M. 2020, ‘As Nuclear waste piles up, scientists seek the best long-term storage solution’, Chemical and Engineering News, 30 March, viewed 12 December 2022, <https://cen.acs.org/environment/pollution/nuclear-waste-pilesscientists-seek-best/98/i12>.


Oreskes, N 2019, Why Trust Science?, Princeton University Press, Princeton.


Oreskes, N. and Conway, E.M. 2010, Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming, Bloomsbury Press, New York.


Ritchie, H. and Roser, M. 2022, Plastic pollution, Our World in Data, viewed 12 December 2022, <https://ourworldindata.org/plastic-pollution>.




Heather Douglas is a philosopher of science who works on the relationships among science, values, and democratic publics. She is an Associate Professor in the Department of Philosophy at Michigan State University. She is an AAAS fellow, and was Senior Visiting Fellow at the Center for Philosophy of Science at the University of Pittsburgh (2021-2022).  She is the author of Science, Policy, and the Value-Free Ideal (2009), The Rightful Place of Science: Science, Values, and Democracy (2021), and editor of the book series Science, Values, and the Public for University of Pittsburgh Press.


The facts, ideas and opinions expressed in this piece are those of the authors; they are not necessarily those of UNESCO or any of its partners and stakeholders and do not commit nor imply any responsibility thereof. The designations employed and the presentation of material throughout this piece do not imply the expression of any opinion whatsoever on the part of UNESCO concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.