Researchers from Texas Tech University have found that anti-vaxxers (those who deny the efficacy of vaccines) are more paranoid than the average person, often overestimating the danger of other causes of mortality too.

Despite the fact that vaccines have a long history and reams of scientific evidence suggesting their efficacy, some perceive them as dangerous. For example, although studies have shown that vaccines have generally been a successful measure against the spread of measles, some exaggerate the occasional adverse reactions linked to the vaccine as evidence of their lack of efficacy and ability to cause harm.

For the study, researchers asked 158 people to fill in a survey rating the prevalence of death from 40 different instances such as cancers, fireworks, and car accidents. As a control the participants were also asked to rate the frequency of neutral or positive events including how often WIllie Nelson concerts of papal visits happen.

In the end, the researchers found anti-vaxxers tended to exaggerate the threat of common fatality types more often than people who are not skeptical of vaccines- judging them to be more dangerous than the reality. They did not however overestimate the chances of positive or neutral events nearly as often.

"We might have assumed that people who are high in vaccine skepticism would have overestimated the likelihood of negative vaccine-related events, but it is more surprising that this is true for negative, mortality-related events as a broader category,"says Tyler Davis, one of the study’s authors. "Here we saw an overestimation of rare events for things that don't have anything to do with vaccination. This suggests that there are basic cognitive or affective variables that influence vaccine skepticism."

"My takeaway is that vaccine skeptics probably don't have the best understanding of how likely or probable different events are," said Mark LaCour, an author of the study and a doctoral student in psychological sciences. "They might be more easily swayed by anecdotal horror stories. For example, your child can have a seizure from getting vaccinated...These cognitive distortions of anecdotes into trends are probably exacerbated by decisions to subscribe to statistically non-representative information sources."

Excited about these findings, the researchers hope that they will provide insight into how best to communicate with anti-vaxxers in the future to convince them of scientific consensus.



Sources: Big Think, EurekAlert