Every one of us runs the same shortcut, and every one of us believes we are the exception. What looks like generosity from the outside is usually something simpler from the inside: tiredness, a deadline, a wish not to look foolish. The remedy is rarely exhortation. It is a change to the situation so that the easier choice is also the better one. The textbook treats generosity as a preference to be revealed. In practice it is a story we tell ourselves after the fact.
What it gets right
It is tempting to call this irrational. It is more useful to ask what it is for. A better account of generosity would begin with the ordinary case rather than the laboratory one. The measure that matters is not what people say about generosity but what they do when nobody is scoring. The textbook treats generosity as a preference to be revealed. In practice it is a story we tell ourselves after the fact.
