Humans are boundedly rational and use heuristics to make decisions, rather than optimise at every turn. It doesn’t always serve us well:
In the months after the 2001 terror attacks, passenger miles on the main US airlines fell by between 12% and 20%, while road use jumped.
Professor Gerd Gigerenzer, a German academic specialising in risk, has estimated that an extra 1,595 Americans died in car accidents in the year after the attacks – indirect victims of the tragedy.
Gigerenzer ascribed the extra deaths to people’s poor understanding of danger. “People jump from the frying pan into the fire,” he said.
“We have an evolutionary tendency to fear situations in which many people die at one time. This is likely a hold-over from when we lived in small groups, where the death of a small part of the group could place the lives of everyone else in jeopardy.
“That’s no longer the case, but it is very difficult to elicit the same fear for the same number of deaths spaced over a year.”