Worried about shark attacks or terrorism?
AuthorsBen Newell, Professor of Cognitive Psychology, UNSW Chris Donkin, Senior Lecturer in Psychology, UNSW Dan Navarro, Associate Professor of Cognitive Science, UNSW The world can feel like a scary place. Today, Australia’s National Terrorism Threat Level is “Probable”. Shark attacks are on the rise; the number of people attacked by sharks in 2000-2009 has almost doubled since 1990-1999. Travellers are at a high risk of getting the Zika virus in places where the disease is present, such as Brazil and Mexico. However, despite their tragic outcomes, these events are all extremely rare. Since 1996, only eight people have been killed by terrorism attacks in Australia. There have been 186 shark attacks in the 20 years from 1990 to 2009. Best estimates indicate that only 1.8 people for each million tourists would have contracted Zika at the Rio Olympics. To be fair, it is extremely difficult to judge the incidence of rare events. So how should we think about these risks? Default to safe Decision scientists study rare events by bringing people into the lab and asking them to make choices. For example, in their Nobel Prize-winning work, researchers Daniel Kahneman and Amos Tversky had people make choices between two options: one safe, one risky. A typical choice might involve a safe option where you’d walk away with $5, guaranteed. Alternatively, you could choose to take a gamble and receive $15 with 90% probability. However, if you lost the gamble, you would have to pay $35. If you’d just take the $5, then you’re not alone. Despite the gamble being clearly better than taking $5, in terms of what you would win on average (0.9 x $15 – 0.1 x $35 = $10), the loss of $35 looms so large in the mind that many of us tend to choose the […]