After studying Psychology for 3 years I am humbled by and extremely confused about the human brain and how it works. Humbled because of the amazing capabilities that have evolved over millions of years, and confused because it is simultaneously the driving force behind the strangest and most dangerous theories, connections, behaviours and actions in history.

One of the most dangerous movements of recent times is that of the anti-vaccination networks, specifically those that say vaccinations (specifically the MMR shot) cause autism. Now I know you’re all sick of the ‘debate’, and I’d be preaching to the choir if I was to tell you that it’s been scientifically debunked, so how about looking at the psychological processes behind this strange conspiracy theory.

Firstly, for those not familiar with the MMR vaccination controversy, in 1998, a theory emerged that the MMR vaccine caused autism. Specifically, the theory argued that the vaccine lingered in the gut, causing gastrointestinal problems which led to autism. This very small study was discredited and debunked. In fact, while the rate of MMR vaccinates has remained constant, the rate of autism diagnoses has continued to soar¹. Along with there being no connection with the vaccine, autism is a largely genetic disease, as scientists have found that if one identical twin is diagnosed with autism, the other twin has about 90% chance of developing an autistic disorder². Also, because this is science, and you’d expect as such from science, I’ve included references of the publications in which I gathered these facts from.

We pride ourselves on being logical and rational beings, above all other animals, capable of intelligent decisions and proud of our newly formed frontal cortexes. Yet this belief is constantly challenged by observing ourselves and others who continually make emotionally driven decisions, whether it’s by believing in a particular religion, or simply buying a chocolate bar because you ‘felt like it’. This is because our frontal cortex is intimately linked to our primary emotions (fear, anger, surprise, happiness, sadness) and these easily take over the function of the frontal cortex. So when your offspring’s health is at stake, what do you think wins out?

Here is a quote from one of the many anti-vaccination websites floating around:

‘The scientific proof of vaccine caused autism has been around for some time but kept from the public by the industry controlled media who trumpet the smokescreen of junk science epidemiology studies that have all been shredded numerous times. Plus, the thousands of parent anecdotes are ignored for obvious reasons’.

Before steam starts billowing out your ears from the sheer ridiculousness, understand that these anti-vaccinators share our brain structures and connections. So what could explain these unfounded beliefs?

A major factor is external explanatory attribution. If you’re unfortunate enough to have a child with a disability like autism, there is the natural inclination to blame something or someone other than yourself to deal with any guilt or frustration you may feel. Everyone does it. We all make explanatory attributions to understand the world and to seek reasons for particular events. In this case, the external blame is placed on vaccines, doctors, the media and ‘big pharma’. No-one wants to be held responsible for their child’s sickness or disease, and with autism, no parent should be. An interesting feature of this psychological theory is the difference in attributions we make about ourselves and others. We tend to blame environmental influences on our behaviour and circumstances (‘I smoke because my job stresses me’), whilst we blame other’s behaviour on their internal choices (‘He smokes because he’s got no will power’).

These attributions flow seamlessly into forming strong and emotional cognitive and confirmation biases. The complaint of parent’s anecdotes being ignored is firstly failing to know that anecdotes don’t count as scientific evidence, but most importantly, is a great example of confirmation bias. We all have opinions and ideas that we wish to be reinforced and supported by others. I think dressing up cats in human clothes is hilarious, and I feel justified and supported when I find other people or groups that share my interest. This confirmation bias is evident in the anti-vaccination groups who actively seek out information that supports their claims and beliefs and ignore those that don’t (or blame it on a conspiracy). This is why they place so much importance on anecdotes. They trust fellow parents/people who share their opinions and are puzzled and insulted when others don’t.

As well as valuing anecdotes from others that support their position, anti-vacs employ the use of the ‘availability heuristic’. This is a cognitive bias tactic that our brains use to help report the frequency of an event based on how easily an example to be brought to mind. If you surround yourself with people who are convinced that a vaccination gave their child autism, and information supporting this theory, then these will be the first examples that come to your mind. But what makes this a vicious cycle of unstoppable madness and dangerous ‘information’ is that cognitive and confirmation biases are so strong and ingrained in individuals, that bringing them to their attention will most likely be ineffective as they will be dismissed by those who hold anti-vaccination views.

Of course these psychological tendencies and theories can be applied to anything in life. They are the core components of large organisations such as religions and cults, and can filter down into the smallest of decisions and opinions in everyday life. So even though you may vehemently disagree with and campaign with every fibre of your being against their movement, it’s hard not to identify with them on a purely human and emotional level.

1 –  Exkorn, Karen Siff. 2005. The Autism Sourcebook: Everything You Need to Know about Diagnosis, Treatment, Coping, and Healing. New York, NY: Harper Collins.

2 –  Lathe, Richard. 2006. Autism, Brain, and Environment. Philadelphia, PA: Jessica Kingsley Publishers.

(This post was originally featured on the brilliant Martin Pribble’s website http://martinspribble.com/ Check him out!)