The question what caused this often hides a choice about where to stop tracing causes.

Causes go back forever, so any answer about what caused something is really a decision about where to stop. Choose one link and it is a personal failing; choose another and it is a system, a history, a piece of luck. The stopping point usually reflects what we already wanted to hold responsible, and it hides inside a question that sounds purely factual.

When you are assigning cause, especially to a person, try extending the chain one link further and see whether the story changes. Do this for yourself as well. You may find you have been stopping early on other people’s mistakes and late on your own, or the reverse, and either pattern is worth correcting.