Why do scientists keep changing their minds?

One reason vaccine holdouts give for not trusting authorities such as the Centers for Disease Control is that these scientists are constantly changing their minds. At first they recommended that we not wear masks. Then they told us to make our own masks. Now those of us who are fully vaccinated don’t need to wear masks—except when we do. That is, we should wear masks indoors where COVID-19 is prevalent or case numbers are rising rapidly. And any time we’re in a medical facility. Or if we want to avoid infecting vulnerable family members. Or maybe we just want to be a good example for children who are too young to get the vaccine. Pro tip: always carry a mask in your pocket.

Why scientists should keep changing their minds

COVID-19 vaccination clinic
COVID-19 vaccination clinic. Shutterstock image.

As we’ve discussed in a previous blog, many members of the general public don’t really understand science. Too many people see it as a collection of immutable—and usually boring—facts.

But science is really a way of thinking about the world. The scientific method is a way of figuring out how the world works. Rather than a static collection of facts, science is constantly evolving as we learn.

Sometimes new data or observations don’t fit with what we thought we knew. We could just stubbornly cling to our “knowledge.”  But it’s much better to rethink what we know in light of the new information. As long as they’re learning things, good scientists need to keep changing their minds. That’s one reason why it’s important to cite the date of a reference, especially if it’s a website that—you guessed it—could change over time.

Two years ago we didn’t even know COVID-19 existed. Since then, scientists have sequenced its genome and developed not just one but several highly effective vaccines. Medical professionals have learned a great deal about how to treat the symptoms. Public health officials have learned how the disease spreads and how to reduce transmission. It’s not surprising that these scientists have kept changing their minds as they develop new information. And because of the urgency of the pandemic, new developments have come in rapid succession.

In addition, scientists usually work in obscurity. They’re not necessarily trying to keep their work secret. But they normally wouldn’t publish it until they’re confident in their conclusions. During the pandemic, we’ve all been watching the latest developments on the nightly news. Often we hear of them before verification is complete, so we shouldn’t be surprised when a spokesperson later “walks back” a too-firm conclusion.

And to complicate matters further, the virus itself continues to mutate. That is, the virus we encountered in late 2019 or early 2020 is not the same one we see today. The delta variant is both more virulent and more transmissible. That means we have two good reasons to be more diligent in our efforts to protect ourselves and others from it.

Video: The Royal Society explains why scientists should keep changing their minds.

Believing in science—and scientists

Because the average person isn’t scientifically literate, they tend to equate scientists who keep changing their minds with flip-flopping politicians. That is, they don’t trust the person who says one thing today and then contradicts it tomorrow. That’s fair enough when we’re talking about unchanging principles. But when the facts on the ground are changing, what we think and say about them should also change. You wouldn’t trust a meteorologist who gave the same weather forecast day after day. So why should you expect the CDC’s guidelines to stay the same?