Monday, March 15, 2010


People are notoriously hopeless at judging risks and benefits, a fact which provides profits to insurers and windfalls to casinos. We fret over very small risks while blithely accepting big ones. More people are afraid of snakes than of cars, for instance, though only 10 Americans per year, on average, die of snake bites while 40,000 die in their cars. What about the safety of our kids? There never (as in “not ever”) has been a single death reported from marijuana overdose, while a dozen teenagers die on football fields in a typical year. What activity have we made illegal?

The “savanna principle” is probably at the bottom of this. Human brains are not hard-wired to understand anything that didn’t exist in the ancestral environment where they evolved. Cars didn’t exist 10,000 years ago, so, while we can grasp the dangers intellectually, we don’t feel them viscerally – not in the way we feel the dangers of poisonous snakes, which were plentiful. Viscerally is the way we make most of our decisions, despite the self-flattering “Sapiens” in Homo Sapiens.

Our poor risk assessments often counteract efforts to keep us safe. Again, cars offer a good example. When drivers know they have four-wheel drive or better brakes, they drive faster and less carefully even in bad weather conditions. Insurers in the UK once offered discounts to drivers of cars with safer brakes. ‘They don't anymore,’ says John Adams, a risk analyst and emeritus professor of geography at University College. There was no reduction is accidents.

There probably is no getting around our emotional responses to different types of risks and opportunities. However, our cortex is good for something, and it behooves us to double check those responses occasionally to see if they make any sense. It might save us some grief.


  1. But does the savannah principle apply to marijuana? Or is that just a result of overprotective parents. :)

  2. In the sense that poisonous plants and fungi were everywhere, and so we are conservative, and likely to listen to warnings. For example there are far many more edible mushrooms than the ones we eat, but there are good reasons not to experiment to find them. We haven't added a new significant food crop in 2500 years. (Football didn't exist 10,000 years ago either, of course, though physical prowess surely was admired.) Still, it is more debatable than the snakes, I concede.