Morale burn rate

Somewhere in his essays (I can’t find now where), Paul Graham states that startups run on morale. It’s hard to argue with that.

If morale is more important than money in the early stage of a startup, is there such a thing as morale burn rate? If the startup burns more morale than it generates over a certain period of time, then the founders will stop working on it.

I’ve been thinking about how to lower this morale burn rate. Is it to lower one’s expectations for success? Or even to drop them completely? Or is it about finding something that works in order to get energy into the startup?

If I find out, I’ll let you know.