Our brain is not a computer; it is a squishy belief engine that can lead us astray in a myriad of ways. Learning to recognize how our brain misleads us can help us think more clearly and make better sense of the world around us. Take airplanes, for example.
Imagine you’re in charge of sending airplanes out to fight a war. The planes that do come back to base have been hit in the spots indicated by the red dots. Where should you add armour to reinforce them? Our first instinct is to say “on the red dots!” This is where the planes were hit: let’s make these areas stronger! But when we slow our thinking down, we realize that this is mistaken. If a plane was hit in these spots and made it home, the damage was not fatal. It is the planes that did not return to base—the ones that did not survive—that we should be concerned about. Indeed, when this scenario arose in World War II, statistician Abraham Wald recommended that planes be reinforced where there were no red dots, assuming that these were the spots that would deal a lethal blow to an airplane.
This is known as the survivorship bias. It’s when we focus on paintings that have been chosen by art historians to be preserved and assume that every painting from that era was just as good. It’s when we concentrate on an old building that has survived in our city and observe that “they don’t make them like they used to,” not taking into account all of the old buildings that have been torn down in the intervening years for not being sturdy enough. It’s when we think that because highly-paid Hollywood actors exist, all we need is determination and hard work to “make it,” without considering the hundreds of thousands of would-be actors who don’t “survive” the process. It’s when we point out a few smokers who lived to be one hundred and turn a blind eye to all the ones who died at 50.
The next time you find yourself looking at a multimillionaire CEO who dropped out of high school and wanting to hear their advice, ask yourself: where are all the high-school dropouts who aren’t multimillionaires?