Post No.: 0157
The ‘availability heuristic’ is the process of judging the size of a category or frequency of an event by the ease or fluency in which specific instances of it come to mind (e.g. the perceived frequency of terrorist attacks in your country after an attack in your country has just been reported in the news, or the risk of burglary after recalling examples of such occurrences amongst one’s own friends and family). If one can more easily think of or remember more examples of something then one will tend to believe that this something occurs with a higher frequency and probability than in reality, and vice-versa. Like other heuristics of judgement – it substitutes one question for a (simpler) one, which sometimes works out fine, but inevitably risks errors.
So if such instances are retrieved from memory more easily then the size or frequency of the category or event will be judged to be large, and vice-versa. Yet one doesn’t actually even need to retrieve from memory or construct a single specific example to have a guess at the size of a category (e.g. which countries have generated more global news stories than others?)
The problem with this heuristic is that salient events most attract our attention and are therefore more easily remembered and retrieved from memory. For example, scandals within political circles attract more attention and always get reported in the mainstream media if found because they are of public interest, so politicians may seem to be more untrustworthy on average than people in the general population, even though millions of crimes committed by people in the general population never get reported in the national news, never grab our attentions and therefore never each get remembered or even each individually become known to exist. We are therefore more likely to exaggerate the frequency of political scandals compared to non-political scandals.
Salience, affect (emotional impact), recency, familiarity, personally experiencing or witnessing something firsthand, personal beliefs, the ease and vividness of imagination, and images and vividly graphic examples, are all greater influences on our sense of availability than the actual frequency of an event, than incidents that happen to other people only, things that one isn’t interested in believing, or mere words or statistics.
A dramatic recent event temporarily increases the availability of its category. For example, a highly media-covered plane crash or a recent terrorist attack will at least temporarily alter one’s feelings regarding flight safety or the dangerousness of the world whilst the issue is starkly on one’s mind and short-term memory; whereas all the far more frequent and lethal road traffic accidents that did not receive any media coverage at all won’t become quite as affecting. The risk in an adventurous expedition will depend on how easy it is to imagine the difficulties or disasters, rather than the actual probability of difficulties or disasters, which could lead to an under or overestimation of the risks. Vivid memories and the mental availability of disasters dim over time though, and therefore so does concern and diligence over time too – hence the recurrent cycles of disaster, concern and then growing complacency (e.g. mass shootings and law change in America).
The cognitive ease or effortlessness in evoking examples of an event is not the same as the actual frequency or probability of that event, so if two groups have equal actual frequency then the group that has more salient or affecting examples will be perceptually deemed as the more frequent group. A judicial error that affects you will undermine your faith in the system more than a similar incident concerning someone else you read about in the papers. Or if one believes that e.g. ESP (extrasensory perception) is real then one will focus less attention on research or evidence that counters the existence of ESP and more attention on those stories that apparently support its existence, and therefore one will find it easier to retrieve these latter stories from memory.
False stereotypes, false beliefs or illusory correlations that are salient or easy to imagine will therefore also affect availability (e.g. regarding behaviours commonly believed to be related to various mental disorders). Perceptually-associated things – possibly due to them being culturally perpetuated by the media and/or gossip – will be judged to be frequently co-occurring, even if the association is actually erroneous or weak in reality (e.g. suspiciousness being associated with shifty eyes rather than any other part of the body).
Therefore the availability heuristic is a mental shortcut that often fails – this fuzzy heuristic means that we feel we don’t need to think so hard, hence we end up not thinking hard about the answers that come to us easily at all, which can skew our perceptions, both high or low, of the true risks of various things. We might even also, afterwards, come up with explanations for these ‘facts’ we believe, to falsely rationalise and reinforce them.
When someone is on a hot winning streak during a game, failure doesn’t come easily to mind, thus the ‘availability bias’ can begin to make such a person feel overconfident. Recency effects and ‘what you see is all (you think) there is’ (WYSIATI) are also why, when people see a team on an unusual winning streak, they tend to think they’re on an unstoppable roll – rather than more logically think that results should soon regress back to the mean (return towards the long-term average).
In a mixed list of an equal number of celebrity males and non-celebrity females, one will tend to think there were more males in the list because the celebrities were more recognisable and memorable. The actual statistical risk of e.g. a train derailment happening may not change, but seeing one coincidentally happen twice in the past week may increase one’s cognitive availability of train derailments and thus increase their perceived risk considerably. Watching too many spy movies recently can make one perceive conspiracies are everywhere. The lack of availability can have the opposite effect and make us underestimate a risk too (e.g. indoor pollution, or house prices plummeting when they only seem to be lately going up and up in the news).
The media therefore plays a huge role in what we perceive as risky or un-risky, and can misrepresent matters when the media-led perceptions of something differ from the actual statistical risks of its availability (e.g. many people erroneously think that Ebola and shark attack deaths are more common than they really are, and underestimate the risks of asthma or sepsis – indeed if you’ve never heard of sepsis (i.e. it has zero availability to you and you cannot even bring one example to mind) then you’ll likely vastly underestimate its frequency).
Very often, things only saliently stand out or get reported in the media precisely because they are rare, controversial and are therefore unrepresentative or too-early-to-confirm-if-absolutely-true. What’s common will be boring, and what’s rare or unique will stand out vividly and be more available and memorable; for better or worse. Salience depends on the context (e.g. sudden noise will attract attention when it’s generally quiet, and sudden silence will attract attention when it’s generally noisy).
So vivid and salient events are easier to recall but they’re vivid and salient likely because they’re the exception rather than the rule. Salient things are disproportionately more prominent and more unforgettable – our fluffy attention is most drawn towards the exceptional, hence these things stand out and are more memorable precisely because they’re unusual rather than common, hence what we’re often doing is over-emphasising the importance of the uncommon and taking for granted the normal (e.g. over-emphasising a nice gesture from an otherwise neglectful boy/girlfriend, or a rare moment of forgetfulness from an otherwise conscientious boy/girlfriend).
This is a reason why fruit machines don’t make a big noise about all those losses yet they make a fanfare for all in the room to see and hear whenever they pay out, or why all lottery winners are highlighted if possible even though the overwhelming majority of players lose – they want to keep the winning and winners available in the minds of players rather than allow minds to focus on all those millions who play these games and lose. This all leads to the fallacy that incredibly improbable events can be more influential and persuasive than more probable events.
The ‘availability cascade’ is when one source exaggerates a claim, which freaks people out, then another source picks up on this emotional angle and exaggerates that, and so forth like a contagion in a network as the public and the media both seek and compete for attention – which all creates a self-reinforcing, collective overreaction (e.g. vaccination health scares). So a non-event can be inflated by the media in a feedback loop with the public until it’s over-exaggerated, everywhere, and becomes all anyone is talking or thinking about. This all in turn affects policymaking because democratic politics is guided by the intensity of public sentiment, at the expense of other possibly more important but mundane public priorities and undramatic topics that slip away from the public’s awareness and availability. (Although one benefit could be that it can help us to focus on tackling a problem or make us more aware of a whole class of problems before they get too big.) Meanwhile, scientists or other people who try to dampen all this overplayed hysteria attract little attention, get crowded-out or are accused of being involved in attempting a cover-up(!) This is why we must question all sources of information and how they may be affecting our judgements.
So we can easily believe in things we shouldn’t, and disbelieve in things we should believe. It’s difficult and tiring to constantly question one’s beliefs, intuitions and impressions and to dispassionately study the cold statistics and read a lot of words, but that’s what one must try to do to counter the availability heuristic and other heuristics when they lead us astray (e.g. just because no one you personally know has ever gotten sunburnt, does this mean that you don’t need to use sunscreen? Or just because a few immigrants have been causing trouble in your area recently, does this mean immigrants are causing problems everywhere?)
Once again, being vigilant against and trying to resist our own biases is possible but requires a lot of ceaseless, conscious effort, which doesn’t come in unlimited supplies. Our intuitions believe that instances of frequent cases are always recalled better and faster than instances of less frequent cases, that likely occurrences are always easier to imagine than unlikely ones, and that associative connections between events are only ever strengthened when the events frequently co-occur – but these intuitions often result in systematic cognitive errors.