Which Experts Should You Listen to during the Pandemic?

As COVID-19 cases and fatalities surge around the world, a parallel surge of predictions and recommendations are competing for our attention. Commentators race to weigh in on this pandemic moment, eager to satisfy a pressing human need: facing an epidemic of both enormous consequence and enormous uncertainty, we all crave answers. We want to keep ourselves and loved ones safe. We want the assurance of knowledge.


But which commentators should we trust? There are many voices, but they often fail to harmonize. Some even sing dangerous tunes. The cacophony requires us to weigh carefully which voices we should heed.

First and foremost, we should filter out those who are addressing issues beyond their intellectual training and competence. In philosophy, this phenomenon has a name: epistemic trespassing. It occurs when commentators holding real expertise in one field intrude into another, passing judgment where they lack crucial competence. Roaming into a field without expert-level insight, trespassers easily slip up.

We have witnessed a cavalcade of epistemic trespassing on pandemic topics. In mid-March, a prominent American legal scholar argued that official estimates for COVID-19 deaths in the United States were radically overinflated. His theoretical model indicated that “about 500” Americans would die. The head of the Israel Space Agency, a military scientist, produced a statistical model predicting that the virus would peak after 40 days and fall to nearly zero by 70, no matter what containment measures are used. Well beyond that 70-day limit in the United States, zero is nowhere in sight.

Then there’s medical treatment. An unlicensed dermatologist from Portland, Oregon, promoted “medical ‘chicken pox’ parties” where people would voluntarily infect themselves with coronavirus. In Iran, some religious leaders have instructed people to use medicinal herbs, oils and fruit juices to guard against the virus.

This sort of trespassing is nothing new. John Barry’s The Great Influenza, a book about the horrors of the 1918 pandemic, describes people stocking up on fraudulent elixirs and hanging garlic around their necks. Newspapers ran advertisements that were hard to distinguish from real articles. A shoe store advertised, “One way to keep the flu away is to keep your feet dry.”

Trespassing by faux authority historically has spread across many scientific fields. One troubling example, described in detail by Naomi Oreskes and Erik Conway in their book Merchants of Doubt, is an elite cadre of 20th-century American scientists who spread misguided messages over the course of several decades on global warming, acid rain and the health risks of smoking cigarettes. Bankrolled by industries with significant financial interests, they confused both public and politicians about what the actual science had established.

Why do people trespass, despite the risks to others and to their own reputations? We presume (appealing to Hanlon’s Razor) that most have honorable motives. But good judgment requires more than just good intentions.

Getting traction in any domain of knowledge—virology, medical treatment and public health in this case—calls for specific skills and knowledge to interpret evidence accurately and make recommendations. Genuine experts have capacities precisely tailored to the problems they tackle, allowing them to reach sound conclusions or at least reduce mistakes. They bring years of relevant training; historical knowledge; and an appreciation of their limits. Of course, even when experts stick to their home fields, they are not infallible, especially when confronting novel challenges. But through their skill true experts are far better at recognizing uncertainties and adjusting their judgments in light of new evidence.

Trespassers lack that well-tailored expertise. What they actually do know does not always transfer to new and different topics. Worse, they often lack the awareness that such tailored expertise exists. Their gaps in knowledge remain invisible to them.

Trespassers believe instead that their admittedly valuable “home field” skills carry over to other fields. Knowing only those skills, they believe they need nothing more to step outside their true circle of competence. They are like the proverbial worker who knows how to use a hammer and thus sees everything as a nail—not fathoming the existence of other tools.

To be sure, newcomers occasionally bring valuable insights to other established fields. In 1915, for example, the German scientist Alfred Wegener, an applied astronomer and meteorologist, famously proposed his theory of continental drift. The vast majority of card-carrying geologists dismissed his ideas, but today core notions of his theory are taught in geology classrooms under the updated name plate tectonics.

But one general lesson for outsiders is that the best recipe for making an impact is through collaboration with experts trained in the relevant discipline.

Coronavirus trespassers strike out alone on social media and in op-ed articles. They may crowd out real experts and science communicators trying to mitigate misinformation. One infectious disease epidemiologist recently complained of “an epidemic of armchair epidemiology.” As a commentator once put it, the proliferation of spurious claims is like “the releasing of dummy hares for serious researchers to waste their time and energy chasing.” It is costly for experts to catch and correct trespassers’ errors and success is uncertain.

While the rest of us navigate hectic, confusing channels of information, the concept of epistemic trespassing can help us decide whom to trust. One key insight is that judging another person’s expertise often requires us to trespass beyond our own circle of competence. So how do we choose which commentators to follow and which to sideline?

Here are three essential questions for trusting more wisely. First, what fields of knowledge are strictly relevant for determining the message’s accuracy? Is the issue a matter for epidemiologists, immunologists or vaccine science?

Second, does the messenger have training and a track record of success, in that relevant field? We non-experts can’t always expect to distinguish trespassers from genuine experts, but our failure is more certain if we don’t pause to ask sharp questions about credibility. Some trespassers may have impressive street cred, such as success in business or an Ivy League degree. Our advice is to not be impressed by these general haloes but instead to focus on specific credentials.

Third, and most important, ask whether multiple and independent sources concur. Do other messengers state the same claim? Is the messenger speaking on behalf of many experts? It is essential to cross-check assertions by those who claim expert status. Trust not any single expert, but experts in the plural.

In anxious times, we all feel the need to know. But as we pursue satisfying that need, we must be cautious. Even the most highly educated and successful among us are not immune to gullibility. Humility about the limits of our own knowledge is imperative, including when trying to identify true expertise in others. Seeking knowledge—now as much as ever—means keeping an open mind, checking sources conscientiously, and sometimes admitting “I don’t know.” Being prepared to make that last confession may be the surest way to ensure our future arrival at the truth.