Jo Nesbø’s The Thirst is my current eye candy book. If you enjoy fast paced Scandinavian crime fiction, I highly recommend Nesbø’s brilliant but alcoholic protagonist Harry Hole. The Thirst is the 11th book in the series and also provided me with an opportunity to return to cognitive biases, something I have written about in the past.
Early in the book Detective Hole makes the following observation in a conversation with a fellow police officer:
“Did you know that there was a serious bus crash in the center of London the same day as the terror attacks in Paris? Almost as many people were killed as in Paris. Norwegians who had friends in Paris started calling, worried they might be among the dead. But no one was particularly worried about their friends in London. After the terror attacks people were frightened of going to Paris, even though the police there were on high alert. No one was worried about travelling by bus in London even though traffic safety hadn’t improved.”
I did some fact checking. Harry Hole’s argument, while intriguing, is a fictional creation. In the November 2015 Paris attacks 130 victims were killed and 416 were critically injured. The closest article I found about a London bus crash in November 2015 was a tour bus accident in August. The driver let go the wheel and hit a tree branch which ripped the top off the bus seriously injuring four people.
While Nesbø’s comparison is a fabrication, the cognitive bias in his analogy is real. A study comparing the likelihood of death by terrorist attack or traffic accident in OECD countries found that the probability of dying in a traffic accident is 390 times greater. If the two probabilities were equal, there would be a 9-11 scale attack every 9.1 days.
What Nesbø is alluding to is an example of the availability heuristic.
Availability heuristics are abbreviated cognitive processes that lead to judgment errors. They are mental short cuts we use for assessing, and attaching weight to, specific events in the absence of complete information. Put simpler: we remember and are guided by events we can easily recall as opposed to less recallable events with a higher statistical frequency. Hence, we overemphasize terrorism because of media attention and our ability to remember specific tragic incidents and ignore bus crashes.
Do you have other examples of the availability heuristic? Leave a comment.