If you believe in some sort of medical conspiracy theory—such as the claim that cell phones cause cancer, or vaccines cause autism—you’re not alone. Nearly half (49 percent) of American adults believe in at least one medical conspiracy theory, and 18 percent believe in three or more, according to a new study from the University of Chicago.
Researchers surveyed 1,351 adults around the country and asked them about their agreement or disagreement with specific medical conspiracies. Just over a third, for example, believe that “the Food and Drug Administration is deliberately preventing the public from getting natural cures for cancer and other diseases because of pressure from drug companies.”
One in five respondents also believe “doctors and the government still want to vaccinate children even though they know these vaccines cause autism and other psychological disorders.”
Fewer respondents (12 percent) believe that “the CIA deliberately infected large numbers of African Americans with HIV under the guise of the hepatitis inoculation program.”
People may believe in medical conspiracies because they provide simple, easy explanations for complex phenomena, according to the study’s lead author, J. Eric Oliver.
“Science in general—medicine in particular—is complicated and cognitively challenging because you have to carry around a lot of uncertainty,” he told Reuters. “To talk about epidemiology and probability theories is difficult to understand as opposed to ‘If you put this substance in your body, it’s going to be bad.’”