Ever seen a sign in a supermarket that says something like “limit of 12 per person” for a product on offer? Isn’t it so contradictory to think the supermarket is limiting the quantity one can purchase! The reason for this sign may surprise you…
We like to think we are maximisers whom evaluate all information in order to make the most accurate decisions and judgements. However, human beings are satisficers who like to save mental energy, therefore making adequate judgements where more accurate insights could be made.
Fortunately, most of the time we are accurate. But there are many instances where we are not… for example when stereotypes are wrongly applied, or rules are relied upon. Cognitive heuristics are the mental shortcuts that we use to help us make decisions but they often lead to bias.
Back to the example introduced above. A study found that consumers on average bought 7 cans of soup when the sign “limit of 12 per person” was present. However, when there was no sign at all, customers on average bought 3.3 cans. It’s a clever marketing strategy that plays on the way the human mind make judgements. This specifically is an example of the anchoring heuristic whereby we latch onto initial information and insufficiently adjust from it when reaching decisions. The consumers therefore saw the number ’12’ and adjusted down to decide how many cans to buy, resulting in the anchoring effect (Wansink, Kent & Hoch).
Research has shown individuals to only rely on these rules when we are uncertain.
Therefore the contradictory results of the next study will shock you… Before deciding the length of a sentence experts in criminal law were either given an irrelevant source, were informed that this demand was randomly determined or randomly determined this demand themselves by a throwing dice. When subsequently deciding the length of the criminal’s sentence, it was found in all three conditions that decisions were contaminated by the initial irrelevant anchor! (Englich et al, 2006). As experts in their field, they should therefore not be uncertain but 100% confident with the decision they have made. In a profession where judgements should strictly be down to fact, evidence and the law, it’s worrying to know that decisions as impactful as the time one will spend in jail, can be influenced by irrelevant information the decision-maker has been exposed to beforehand.
You would assume it’d therefore be sensible to know about these cognitive heuristics so one has better chance at avoiding them in influencing our judgements. This may not be possible… Wilson et al (1996) explicitly informed participants that there would be an anchor that may “contaminate” their guesses of how many physicians were listed in the local phonebook. A control group were given no warning and no anchor. The experimental group’s guesses were still higher and more inaccurate than the control even though they were warned! It seems that no-one and in no way can we be immune from the biases that our mind drafts up.
To make you think: When being diagnosed at the doctors, clinicians are likely to use the ‘representative heuristic’ by comparing your symptoms to those most stereotypical of disorders. This can lead to issues…
- If you find this interesting, I highly recommend the book “Unpredictably Irrational” by Dan Ariely as well as his other books