“Humans have an inherent tendency to infer other people's intentions from their actions.” — Blakemore
We blame other people for their mishaps but never ourselves when we do the same. Why? Because assuming causes helps us to make sense of the world.
The fundamental attribution error is just a continuation of a wider pattern: we blame individuals for what happens to them because of the general psychological drive to find causes for things. We have an inherent tendency to pick out each other as causes; even from infancy, we pay more attention to things that move under their own steam, that act as if they have a purpose. The mystery is not that people become the focus of our reasoning about causes, but how we manage to identify any single cause in a world of infinite possible causes.
Even the way I described cause-seeking as an “inherent tendency” is part of this pattern. I have no direct access to what causes the results of experiments that have made me think this, just as I would have no direct access to what caused the man to wake as the leaf fell. I assume a thing, hidden, somehow, underneath the experiments – an inherent tendency for humans to identify each other as causes – which I then rely on to tell you what I'm thinking.
That thing might not exist, or might have a reality very different from how I describe it, but we are forced to rely on assumptions to make sense of the world, and these assumptions create a reality of causes and essences that seems solid, despite its uncertain foundation.
This all might sound overly philosophical, but once you are switched on to this tendency to invent essences you'll hear them everywhere.