We put a big weight on very likely or unlikely events and put almost no weight on anything that happens in between. The difference between a 0 percent and 5 percent probability feels huge because it creates possibility. The difference between 100 percent and 95 percent also feels meaningful because it creates or eliminates risk. But the difference between 50 percent and 55 percent barely factors into our decisions. The closer we get to certainty, the more we weight a probability, but mathematically, a 5 percent increase should be given equal weight no matter what.
