An Indian Survivorship Bias Example
Many of you must have seen that drawing of a World War II plane with red dots on it.
It explains Survivorship bias, a bias that statistician Abraham Wald figured out.
Simply put, survivor bias is our tendency to view a situation or pattern as a comprehensive representative sample, often without considering what might be missing from that picture.
For instance, the WWII plane with red dots was a study Wald and his team carried out to determine which parts of returning Allied jets were hit the most by enemy gunfire, so as to reinforce those parts and make them stronger.
It was then that Wald realized that those parts were actually stronger, as all those jets had made it back to base safely. So instead, they focused on reinforcing the other parts, since clearly jets hit on other weaker sections never survived to tell their side of the story.
In India, there has been a belief among many of the older folk that children or people with big/long ears live a longer life, compared to those with smaller ears.
Interestingly, while most of our body shrinks with age, our nose, earlobes and ear muscles keep growing. Which means our elders had the concept backwards.
It was not that those born with bigger ears lived longer. But rather that those who lived longer, had ears that simply had a longer time to keep growing, and are therefore, relatively bigger in size.
