Survivorship Bias

During the early wars, X-Wing fighters suffered heavy losses in dog fights with imperial fleets and strategic targets. Crews had a 1 in 4 chance of getting shot down and killed every time they flew. Even the X-wings that made it back were often riddled with holes. To protect the crews, the initial thinking was to add armor plating to the areas where most of the holes were observed in the fighter jets that limped home (the wings and tail).

The engineers made the same mistake most of us made. They were studying the success stories and trying to learn from the winners. But the data they were observing was biased in that it only contained information that survived, hence the term “survivorship bias”.

What they needed to do was study failures. The X-Wings that got shot down were hit in the cockpit and fuel tanks, but it was hard to figure this out because these planes crashed in places where they could not be easily studied.

Survivorship bias is our tendency to study the people or companies who “survived” or were victorious in a certain situation while ignoring those who failed. In many endeavors, “the failures” used the same principles as “the winners”, but they were not so lucky and ended up failing.