The Psychology of Conspiracy Theories

To nobody’s surprise, Donald Trump, the billionaire front-runner for the US Republican party’s nomination for presidential candidate, has continued to spread his views on the dangers of vaccination. Trump is no stranger to controversy, least of all when it comes to airing his much-debunked ideas that vaccines cause autism. He has long insisted that his anecdotal evidence proves that autism is rife and is being directly caused by vaccinations, specifically but not exclusively by the MMR vaccine.

Trump again decided to express his opinion last night on CNN’s televised debate, which went largely unchallenged by one of his other nominee contenders, Dr. Ben Carson. They both seemed unaware that rather than there being an autism epidemic, there is a growing risk instead of a measles epidemic.

A popular theme emerges when we examine this type of conspiracy theory – that of conflated political concern. We take a genuine and understandable worry about the size of government and its potential role and interference into citizens’ lives, but then we inflate this into something that becomes inaccurate in the face of science. Vaccinations are an incredibly important part of a child’s development, but does or should a parent’s right to choose what is best for their child override that? Unfortunately the nuances of that genuine debate are overshadowed by bad science and the idea that the government or ‘Big Pharma’ are somehow poisoning children for their own selfish ends.

The majority of Americans believe vaccines to be safe, regardless of political belief, but the opinion is clearly split between those who feel vaccines should be mandatory and those that feel there should be some form of parental choice.

Dan Jolley and Karen Douglas demonstrated in an excellent study in 2014 that exposing people to anti-vaccine conspiracy theories made them less likely to vaccinate compared to controls. Their findings helped demonstrate how conspiracy beliefs can have serious real-world consequences, and can have a role in shaping health-related behaviours. Interestingly, the effect of the conspiracy theory could be explained in part by participants’ existing perception of the dangers of vaccines, alongside their feelings of powerlessness, disillusionment and mistrust in authorities.

So what can we do about it? 

A very recent study published earlier this year may give us some answers. Zachary Horne and colleagues from the psychology departments at the University of Illinois and University of California found that the best way to positively impact people’s attitudes to vaccination was not to try and counter existing anti-vaccination theories.

Instead, they found that by highlighting factual information about the dangers of communicable diseases, such as measles, had a significant effect on attitudes surrounding vaccination. Participants were shown short passages written by a mother whose child had contract measles, alongside pictures of children with measles, mumps and rubella, stressing the importance of vaccinations. By making people understand the consequences of failing to vaccinate they found the change in attitudes to be far greater than any form of correction of the bad science about the dangers of vaccinations.

Could showing images of ill children counteract anti-vaccination belief?

Worldwide, there are 400 deaths a day from measles, but because the successful vaccination programmes of first world countries have more or less eradicated this terrible disease, we are in danger of forgetting just how serious it is. So, perhaps an admirable Twitter campaign could instead remind Trump and others of the dangers of not vaccinating children, rather than the debunked science behind their theory? This research opens up a promising new avenue for delivering parents accurate information but also reinforcing the importance of vaccination.