Anchoring Numbers


Research on priming shows that our thoughts and behaviour are anchored by external stimuli. This extends even to our thoughts about numbers. Daniel Kahneman writes in Thinking Fast and Slow that people’s minds are frequently influenced by a totally uninformative number.

He tells the story of an experiment with German judges. These judges had an average of more than 15 years on the bench. Each judge separately was asked to sentence a woman caught shoplifting. The experimenters rolled a dice that was loaded to a 3 or a 9. Immediately after the dice came to a stop, the judges were asked how many months would you sentence her to prison. On average, those who rolled a 9 sentenced her to 8 months. Those that rolled a 3 sentenced her to 5 months.

What’s even scarier is that a frivolous reference to a ridiculous amount of damages can anchor the thoughts of judges and juries. For example, in some jurisdictions in the United States, the size of damages in personal injury cases are capped at a million dollars. Kahneman notes that this rule might benefit defendants by limiting awards of damages above $1 million, but the anchor also pulls up the size of most awards that would otherwise be smaller. This is because a message unless it is rejected as a lie, will have the same effect on our thoughts regardless of its reliability.

The anchoring effect can be seen in Ontario lawsuits as well. For instance, most insurance policies for motor vehicle accidents cover policyholders up to a $1 million in damages. Therefore, plaintiff’s lawyers tend to claim a million dollars every time in motor vehicle accidents regardless of the severity of the injuries. I would venture that this ends up pulling up the size of most settlements.