The Availability Heuristic is a mental shortcut that helps in decision making by weighting the importance of relevant information by how easy it is to recall. Based on the ‘availability’ of information we can make faster decisions than if we were to recall all eventualities to base our decisions. For example, if I am to ask you “which alcohol is most likely to cause you a hangover?” You will most likely recall immediately a recent and bad hangover and base your decision on that. This allows a fast and quite possibly accurate answer. The alternative would be to recall every hangover you’ve had and the responsible alcohol, then you would run a statistical analysis. This would be very time consuming.  Whilst extremely useful, this heuristic can often leave us prone to error if we place too much emphasis on an event because it is extremely fresh in the memory or particularly vivid. For instance you may purchase flood insurance when in the aftermath of a well publicised flood, even though in the area that you live, a flood is extremely unlikely.

Medical Example:

An example of the Availability Heuristic in medicine is when a person overestimates the likelihood of complication based on the number and potency of stories shared by your social network and popular media. The Mumps Measles and Rubella vaccination was reported to be linked to autism 1998. This connection garnered huge attention in the media until a causal link was disproven – the Dr responsible for the study Andrew Wakefield has been struck off as a doctor in the UK. However their is still widespread belief that MMR causes autism and this is largely due to the availability heuristic. People are able to more readily recall the story of the link, than the story of it being discredited.

Example of Utility:


You can try and guide this heuristic towards more objective decision making by sharing anecdotes of statistical likely outcomes and ‘business as usual’ stories. You can also force people to recall memories of the most likely outcome, “we all know people that have had the MMR vaccination without complication” this is because et cetera, et cetera. Another solution is to include statistics for probable outcomes in a similar format to those used in neutralising the Neglect of Probability bias. A graphical representation such as a pie chart helps humans quantify probability better (something we are notoriously bad at).


If you are looking to change a person’s behaviour you can utilise the availability heuristic. The most common diseases such as cancer, diabetes and heart disease are widely reported in the media and we all have a story close to home of one of these diseases affecting a loved one. To ask for behavioural change (such as quitting smoking) we can ask an individual to recall information designed to positively affect their decisions. I.e. “think of a person you know that has had a heart attack or had heart ‘surgery’ – you know that this outcome is likely and to avoid this happening to you call the smoking cessation number.