‘Expertise’ shouldn’t be a bad word – expert consensus guides science and society

A growing distrust of expertise is reshaping the terrain of science in the United States.

Since the pandemic, the partisan divide over science has widened dramatically. While 77% of Americans have at least a fair amount of confidence that scientists act in the best interests of the public, that breaks down to 90% of Democrats and 65% of Republicans.

If people think scientists are trying to impose their political beliefs rather than expressing honest scientific judgments in the pursuit of truth, public trust in expert consensus will continue to erode.

With recent events, such as Robert F. Kennedy Jr. replacing the expert vaccine panel at the Department of Health and Human Services, and the Trump administration threatening to withdraw research funding from universities that don’t follow its ideological dictates, the political divide in public perception may grow even deeper.

As social scientists who study the role of science in society, we are deeply concerned about the decline of public trust in expertise, which is often fueled by politicians who manipulate people’s suspicions about experts. Skepticism is sometimes justified, of course. But a system based on expertise is the best one modern democracies have come up with to offer guidance on the various complex issues they face.

Who is an expert?

Before you can place your trust in a community of experts, you need a way to determine who counts as an expert. Modern societies usually do this through a sequence of training within accredited schools and universities – institutions whose reputations depend on their ability to train reliable and trustworthy experts.

Unlike the ancient alchemists’ guilds or modern elites, science is not secret, nor gated by family descent or social ties. Today anyone is permitted to become a scientific expert by attaining academic degrees and certifications and establishing a public track record of published research, teaching and contributions to one’s field.

The government also plays a critical role by requiring doctors or engineers to hold certain degrees or by granting universities formal quality certifications, such as accreditation. As an individual, you can’t evaluate the trustworthiness of every person claiming to have expertise – whether a heart surgeon or an electrician. The governmental license carried by these professionals makes that unnecessary.

In any field of knowledge, there is a web of legitimacy, knotted together by visible signals of trust, such as degrees, publications, affiliations and accreditations. Expertise is a team sport.

What is expert consensus?

The most reliable guidance is based on a rigorous group decision-making process, in which people with diverse training and experience contribute their expertise to a dialogue aimed at reaching consensus. The scientific approach to consensus is transparent and deliberate: Scientific consensus processes – such as the National Academies consensus study process, or a PRISMA review – are systematic in incorporating the credible evidence that is available and synthesizing different expert judgments.

The system, honed over decades, is based on the theory that better decisions can be achieved by systematically aggregating many independent opinions – if the group is well trained, draws from a common body of evidence, relies on a common understanding of research practices, and each of its members are able to independently weigh the evidence.

Such communities of experts arise in many settings, from engineers recommending building codes to epidemiologists proposing policies to contain a viral epidemic.

An expert community doesn’t need everyone to be right – or even to agree – in every case for the process to generate useful results. As long as each person is usually right and the community deliberates systematically on the basis of reason and evidence, the resulting consensus will be the best that can be achieved within the limits of current knowledge.

In short, expert consensus requires trained experts, common evidence and systematic deliberation.

Professional consensus vs. individual opinion

Expert consensus doesn’t mean that experts agree on everything, or that everyone must agree with the experts. In a democracy, expert advice is valuable, but it’s not the last word.

The U.S. Bill of Rights enshrines the idea that freedom of speech is fundamental to good government and to leading good lives. But there’s a distinction between speaking one’s mind and speaking from authority. Experts have a right to express their personal opinions and also a duty to exercise care when speaking in areas of their expertise.

This distinction is at issue in the Chiles vs Salazar case before the Supreme Court. It centers on a Colorado state law that prohibits so-called “conversion therapy” for gay or trans children.

Does doing so violate the free speech rights of therapists? It’s not illegal to believe trans children can be talked out of being trans, it’s just illegal to pursue that practice as a licensed professional, because medical experts have reached a consensus that conversion therapy is both useless and harmful.

Expert consensus is necessary to make sound decisions based on science and evidence, but that doesn’t mean experts must abstain from politics or refrain from expressing dissenting opinions. In fact, political restrictions on scientific debate weaken science, as seen in repressive societies.

What does expert consensus provide?

In our fractious political climate, people sometimes think divergent expert opinions mean that consensus does not exist, or no experts can be trusted. Some people say, “Do your own research,” which often leads to rejecting consensus and falling victim to conspiracies and disinformation.

In practice, consensus is compatible with substantial disagreement. In many fields, scientific consensus deals with broad patterns rather than individual cases. For example, medical experts may agree on the nature of a specific condition, and the average efficacy of a given treatment, yet make different predictions about the benefits for a specific patient.

Society faces pressing questions about the behavior of complex and uncertain systems: How much is climate likely to change if CO₂ emissions continue at the current rate – and what ecological changes should we expect? What accounts for changing cancer rates – and what are the most promising paths to develop a broad “cure”? Are AIs developing intelligence and self-awareness – and how can they be designed to be behave safely? What social institutions are essential for human flourishing – and how can they be preserved?

It’s the fundamental role of democratic government to determine which goals we as a society pursue and how to balance competing values. And when we face high-stakes issues involving complex systems and uncertain approaches, scientific expert consensus can act as an honest broker to provide a menu of possible approaches and predictions for each one’s likely consequences.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Micah Altman, Massachusetts Institute of Technology (MIT) and Philip N. Cohen, University of Maryland

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Micah Altman received research funding from the National Science Foundation and the Andrew W Mellon Foundation to conduct research related to the science of science, and related to open science.

Philip N. Cohen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.