What is Survivorship bias (and how to avoid it)

During the middle of the blitz, the allies needed to protect their pilots.

They were being shot by German plans and anti aircraft guns but the distribution of bullets wasn’t even.

Fortunate Abraham Wald knew about this cognitive bias and made the right choice.

Survivorship bias is when we focus on those who are left rather than identifying patterns from those who didn’t make it.

This can lead to noticing the wrong pattern and ignoring the right pattern.

Want an example?

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If the allies had reinforced the locations where their planes that survived were shot, they would have wasted material.

The locations where they weren’t shot were the real risk areas as plans that were shot there didn’t survive.

But how does this affect us?

When we listen to life lessons from successful people, we have to be careful for survivor bias.

The classic example is a person who won the lottery and says “you’ve just got to believe in yourself and work hard.”

But the majority of lottery players never win.

Focusing on success stories leads to bad decisions like

Without looking at failures, we can ignore our own faults.

So how do we overcome survivor bias?

The main tool is proper perspective.

Knowing if a survivor is the exception or the norm helps us evaluate their stories and experience.

And looking at patterns in failures can help us avoid those same mistakes

Survivor bias shows that we tend to focus on the data of survivors but sometimes we just need to avoid what unifies those who don’t survive.