We don't always behave the way economic models say we will. We don't save enough for retirement. We order dessert when we're supposed to be dieting. We give donations when we could keep our money for ourselves.
Again and again, we fail to act rationally and selfishly — the way traditional economics expects us to.
We've seen this during the coronavirus crisis: People selflessly mobilizing to help each other, like the retired Kansas farmer who sent an N95 mask to New York to help a nurse or a doctor.