Vaccines are one of the most significant public health breakthroughs in history, saving countless lives and preventing untold harm. However, vaccines and the public health policies surrounding them currently face challenges in their acceptance. Almost one-third of Americans oppose mandatory vaccination to attend public schools and less than half think that scientists have a good understanding of the effects of the measles, mumps and rubella (MMR) vaccine. Given the importance of vaccines in protecting public health, understanding public hesitancy about vaccination is an important area of inquiry.
In a new study published in the journal Social Science & Medicine, Dr. Timothy Callaghan, assistant professor in the department of health policy and management at the Texas A&M School of Public Health, joined colleagues from the University of Pennsylvania and Utah Valley University in exploring the effects of knowledge and misinformation on attitudes toward vaccine policy. In this study, the researchers used a nationally representative survey to measure what Americans know about autism and the misinformation they hold about vaccines and autism. The survey also asked respondents whether they thought they knew more or less about the causes of autism than medical experts, whether parents should be able to decide to not vaccinate their children and how much they trust medical experts and non-experts like friends and family or celebrities in deciding vaccine policy.
[Photo: Dr. Timothy Callaghan]
Many factors have been found to play a role in anti-vaccine attitudes, such as religiosity, political ideology, gender, age, income and education levels, but little work has been done on how an individual’s knowledge affects their confidence in that knowledge and subsequently their attitudes toward vaccine policy. Previous research has shown that people possessing low levels of knowledge in various areas tend to be overconfident in their knowledge, the so-called Dunning-Kruger effect, which is likely due to those people lacking the knowledge needed to properly assess their own expertise.
The study hypothesized that people with low levels of autism knowledge and who were misinformed about the link between vaccines and autism would be more likely to be overconfident in their own knowledge, thinking they know more than medical experts about the causes of autism. Furthermore, the researchers hypothesized that individuals who thought they knew more than medical professionals would be less supportive of mandatory childhood MMR vaccinations and the role that medical experts play in determining vaccination policy.
“Our research found that about one-third of respondents believed they knew as much or more than medical experts about the causes of autism,” Dr. Callaghan said. “People who knew the least about the causes of autism and who were misinformed about the link between vaccines and autism were more likely to believe they knew more than medical experts and were less supportive of mandatory vaccinations. They were also more likely to place greater emphasis on the role of non-experts in vaccine policymaking.”
The authors state that their study is a first step toward a better understanding of how knowledge, misinformation, and overconfidence relate to vaccine policy and points to several future research opportunities. Further research studying how Dunning-Kruger effects influence other health policies and which non-experts less knowledgeable individuals trust will provide important additional information.
“This study brings additional insight into American attitudes toward vaccine policy and demonstrates that researchers and policymakers need to focus not only on improving public knowledge, but also on combating misinformation related to vaccines,” Dr. Callaghan said.
By addressing overconfidence and the policy attitudes that come with it, policymakers will be better able to counter anti-vaccine attitudes and maintain the currently high rates of vaccination in the United States to prevent disease and improve public health.”