Why you can't change an anti-vaxxer's mind.

The next time you find yourself in a head-smacking debate with an anti-vaxxer, don’t even bother to engage.

A US study has just found that there is no way you can change the mind of someone who has consciously chosen not to vaccinate their children.

Depressing, we know.

The study, published in Pediatrics, tested four theories each designed to dispel the myths surrounding the measles-mumps-rubella (MMR) vaccine. The results will disturb you.

The first group, “Autism correction”, were explained (with actual science!) that it’s completely false to claim that there is a link between the MMR vaccine and autism.

It assured parents that the MMR vaccine is “safe and effective”. The second group called “Disease risks” involved telling parents of the risks –  like you know, DEATH – associated with contracting the measles, the mumps, or rubella.

Group three, “Disease narrative”, were told a true story about a 10-month-old who nearly died after contracting measles from another child in a doctor’s waiting room. The fourth and final group were shown disturbing images of children who have diseases, which could’ve been prevented by the MMR vaccine.

The only group that had a significant breakthrough amongst the 1,759 Americans surveyed was group one, which focused on correcting misinformation around autism.

As for “Autism correction,” it actually worked, among survey respondents as a whole, to somewhat reduce belief in the falsehood that vaccines cause autism. But at the same time, the message had an unexpected negative effect, decreasing the percentage of parents saying that they would be likely to vaccinate their children.

So even though the parents now understood there wasn’t no link between vaccines and autism, they STILL weren’t prepared to vaccinate their children against these preventable childhood diseases. In fact, it made them more defensive about their choice.

Or, in other words beyond help.

According to Chris Mooney of Mother Jones, this is due to the ‘backfire effect’:  “In this group, the likelihood of saying they would give their kids the MMR vaccine decreased to 45 percent (versus 70 percent in the control group) after they received factual, scientific information debunking the vaccines-autism link.”

“Looking more closely, the researchers found that this occurred because of a strong backfire effect among the minority of test subjects who were the most distrustful of vaccines.”

Or, in other words beyond help.

Overall the least successful messages were “Disease narrative” and “Disease images.” Hearing the list of risks that could happened actually increased respondents’ likelihood of thinking that getting the MMR vaccine will cause serious side effects, from 7.7 percent to 13.8 percent. Similarly, looking at the disturbing images of preventable childhood diseases increased test subjects’ belief that vaccines cause autism.

Sadly, the research concluded that “no intervention increased intent to vaccinate among parents who are the least favorable toward vaccines.”

However, not all is lost. A separate study concluded that when parents were prompted to think of vaccination as one of the steps you take to protect a child, like buckling a seat belt, they had a more successful outcome.

James Randi Educational Foundation and Women Thinking Inc. showed that reframing the vaccination argument to be about a lack of action and presenting their children with a real threat akin to a car crash, parents can visualize the harm that can result from their unwillingness to act. According to the authors, it’s an uncommon strategy, but so far has proven to be an effective one.