HOW TO EXPECT THE UNEXPECTED

From tarot cards to forecasts of Armageddon, a mathematician examines the psychology of predictions, debunking myths and setting an agenda for clear thinking.

It’s human nature to want to know what is going to happen in the future. However, writes Yates, author of The Math of Life and Death, doing so with a useful degree of probability is extremely difficult—or even impossible. The author pleasantly explains the tricks used by psychics and charlatans, which usually involve telling paying customers what they want to hear. He tracks numerous apocalyptic predictions and the reasons given by the forecasters for their obvious failure. There is also a tendency of people to see patterns in events and data that don’t exist. Random distribution can throw up apparent causations and connections, but they are really no more than background noise. Humans think in linear terms, assuming that the future will be like the present and therefore precise extrapolations are possible. Not so, says Yates. There are too many variables to consider. True, linearity is needed for everyday existence, but when it comes to making predictions, it is more hindrance than help. The author examines the different types of delusional thinking and outlines the mathematics of probability, and he devotes a useful chapter to chaos theory. The only field with a scientific basis seems to be short-term weather forecasting, although even there, things can go disastrously wrong. Math-based models can be important tools, with the proviso that the output is only as reliable as the input. In the end, there is no perfect prediction method. The best we can do is think broadly, be prepared to change our minds in light of new evidence, and understand our own biases.

Yates’ tour of the predictions business covers much interesting ground, which he tills with an entertaining sense of humor.