Why We Disbelieve Science, Consider Conspiracies

Sep 22, 2014

Credit Gabriel Rocha / Flickr

Fluoridated water reduces cavities, as scientific studies have repeatedly shown. Yet for decades, public health and government officials have had to defend fluoride in public drinking water, against at-times outlandish conspiracy theories. It’s a battle currently playing out in Charlotte. WFAE’s Ben Bradford examines why we have trouble believing the science.


“Do you realize that fluoridation is the most monstrously conceived and dangerous Communist plot we have ever had to face?” General Jack Ripper says in the film Dr. Strangelove.

In the film, Ripper’s reason for launching a nuclear attack on the Soviets—to protect “our precious bodily fluids”—was an actual conspiracy theory when cities first began fluoridating their water in the 1940s.

In the decades since, the rationale has varied from communist plot to corporate dumping of industrial waste to simply unspecified reasons, but throughout the underlying theory “fluoride is poison” has remained prevalent and unchanged. A large body of research shows reason plays little part in how we perceive risks, whether the safety of fluoride, genetically-modified foods, vaccines, or x-rays.

“The way we feel about them is a feeling. The word feeling matters,” says David Ropeik, a consultant and author about risk perception and communication. “The definition of the word “risk” is the probability of something bad happening, and bad is subjective, it’s a feeling.”

We feel that adding a chemical to our water must be bad, and then we find ways to rationalize it.

“We tend to seek out, interpret, and weigh information, based on our prior beliefs. And often times without sufficient regard for evidence for or against those prior beliefs,” says Ohio State psychologist Ellen Peters.

The same confirmation bias leads us to feel the referee is always out to get our team. Peters and her colleagues have similarly shown our worldview skews our views of science. It is why so many conservatives discount climate change and liberals overrate the hazards of nuclear energy—despite a lack of expertise, we disagree with the scientific consensus.

Peters says we can fight that tendency.

“Say, ‘Okay, I know I really believe this, but let me try to think about someone who believes like this, and let me try to get to that person’s shoes for a minute,’” Peters says. “And now, look at the data gain. Do I still think the same thing?”

But, ultimately, we usually side with what feels right, whether about fluoride or another scientific issue. And if we want to follow the facts, we have to be willing to challenge our beliefs.