'Mental model' approach shown to reduce effects of misinformation about mRNA vaccines

Correcting misinformation after it has gone viral is a common way of informing the public that what they've encountered may be inaccurate, lack context, be unproven, or be demonstrably false. But repeating a misconception when refuting it carries the risk of spreading it to a larger audience, especially because the people who read a fact-checking report may not be the same ones who were originally exposed to the worrisome information.

To overcome these challenges, researchers at the Annenberg Public Policy Center (APPC) of the University of Pennsylvania tested the effectiveness of a "mental model" approach to presenting scientific information. Such an approach entails exposing people to visual, verbal, or animated models to teach them scientific or medical concepts so that they either have the tools in place to identify misconceptions before encountering them or can use the model, once they learn it, to override existing misconceptions.

APPC researchers found that using a mental model approach to inform people about relevant facets of science undercuts the effect of exposure to misconceptions, regardless of whether the models were presented before or after the misinformation.

In a new study published in the Proceedings of the National Academy of Sciences (PNAS), researchers led by APPC Director Kathleen Hall Jamieson tested two mental model-based interventions to counter unwarranted fears about messenger RNA (mRNA) technology, the life-saving innovation that revolutionized Covid-19 vaccine creation. It is being used to develop vaccines against potentially deadly health risks including melanoma, pancreatic cancer, flu virus, respiratory syncytial virus, bird flu, HIV, dengue virus, and Lyme disease.

Misconceptions about the effects of mRNA vaccination

Messenger RNA technology has come under attack from critics who allege that vaccines created with it may change a recipient's DNA. These critics claim that stray DNA left over from the vaccine manufacturing process could integrate into a recipient's own DNA and thus increase the risk of cancer and heritable effects. Such fears have been raised by Florida State Surgeon General Dr. Joseph Ladapo, among others, who has discouraged the use of mRNA Covid-19 vaccines in his state. These unwarranted fears led Tennessee legislators to expand the state's Food, Drug and Cosmetic Act's definition of "drug" to include "food that contains a vaccine or vaccine material." They also influenced a Minnesota bill that would designate "mRNA injections and products as weapons of mass destruction" and prohibit "mRNA injections and products."

Experts such as Peter Marks, former director of the FDA Center for Biologics Evaluation and Research, say it is implausible that residual DNA fragments will find their way into cell nuclei and be incorporated into chromosomal DNA. The Centers for Disease Control and Prevention (CDC) says, "COVID-19 vaccines do not affect or interact with our DNA. These vaccines do not enter the nucleus of the cell where our DNA (genetic material) is located, so they cannot change or influence our genes."

The mental model experiments

Jamieson said in a Q&A interview with PNAS that people "create mental models to make sense of how the world works and are disposed to rely on them instead of formal rules of logic when deciding what is true." Instead of citing authorities saying that fears about DNA integration are unwarranted, this mental model approach educates people about how mRNA vaccines work and/or how cells protect their DNA from foreign DNA fragments.

In preregistered experiments, the APPC researchers tested two mental models. The first uses a variant of the "bypassing" approach theorized by Penn PIK Professor Dolores Albarracín, director of APPC's Communication Science division, and her colleagues. Without mentioning the problematic claim, this model offered respondents a graphic showing how mRNA vaccines work and evidence about the safety of mRNA vaccines, anchored in a "coherent, detailed structure of knowledge." The second model works by "foreclosing" – it details the ways in which human cells "protect against or destroy foreign DNA," thereby neutralizing the supposed threat of foreign DNA. To foreclose the DNA integration claim, the researchers used a 105-second animation that depicts how cells protect themselves against foreign DNA.

The study involved showing groups of respondents in the two experiments (n=1,540 and n=2,038) varying combinations of the misleading claims and the two scientific models expressed as graphics, text, or animation.

"We found that respondents who saw the problematic claims along with the mental models were more likely to answer questions in an evidence-based manner than those seeing the problematic claims alone," Jamieson said. "These experiments suggest a promising approach for overcoming some of the challenges that face the usual uses of inoculation and fact-checking."

Since pre-emptive exposure to the models could occur in middle, high school, and college courses, future research could test whether this approach in a classroom setting increases students' acceptance of the descriptive information about how mRNA vaccines work and how cells protect themselves from foreign DNA.