In a similar vein to the recent The Decisive Moment, Dan Gardner’s Risk is an exploration of the way our brains are divided between instinctive and rational thought – throughout, Gardner talks about the differing reactions of Gut (instinctive thought) and Head (rational thought). He also refers throughout the text to several key principles that Gut uses to make its determinations, such as the Example Rule (if you can think of an example of something, you are more likely to be judge it to be plausible), and the Anchoring Rule (whether you like it or not, if I mention there are 530 words in this review, and then ask you for a numerical estimate of something else, you are likely to make your estimate with reference to my original number).

The key principles are lucidly explored with good use of examples, and a clear explanation of why our brains have evolved the way they have (don’t read the next sentence if you’re in Kansas) – they are very suitable for making the judgments required of hunter-gatherers on the plains of Africa, but not really for making snap judgments in the modern world of mass media, democracy, air travel, terrorism and all the rest of it. We have simply not had time to evolve the way our brains work to cope with all the inventions the human race has come up with over the years (ironic, isn’t it?).

Having explained the way the brain works, Gardner is specifically interested in explaining the ways in which it is incapable of judging and assessing risks as they are presented to us. We are constantly fed scare stories by the media (who of course have the same brains that we have to help them in their judgment of what to write and broadcast), but we constantly overestimate risks: from chemicals, from disease, from terrorism, from crime, and even the chances of winning the lottery. We are lousy at odds. Consider the fact that, shocking as the death toll from 9/11 was, half as many people again died on the roads in the US as a direct result of avoiding air travel – yet of course that doesn’t get reported in the same way. Many of the risks we are showered with information about – abduction of children by strangers, road rage, getting cancer from this chemical or that foodstuff – are so small as to be what statisticians call de minimis i.e. so tiny as to be mea