Benjamin Franklin's Autobiography contains a short account of political management that he presents as a maxim and that turns out to be an experiment.
A member of the Pennsylvania Assembly was opposing him and had made a speech against him. Franklin did not try to win him over with favors or flattery, which he explicitly says would have been the obvious approach. Instead, having heard the man owned a rare book, he wrote asking to borrow it for a few days. The book was sent. Franklin returned it a week later with a note of thanks. The next time they met in the House, the man spoke to him — which he had never done before — and with civility. They remained friends for life.
Franklin's own summary is the useful part: He that has once done you a Kindness will be more ready to do you another, than he whom you yourself have obliged.
The proposition inverts the intuition of chapter one. There, a gift creates a debt in the recipient. Here, a favor creates warmth in the giver. Both are true, and they are not in conflict, because they run on different mechanisms.
Jon Jecker and David Landy tested the Franklin version in 1969. Subjects won money from an experimenter in a rigged task. In one condition the experimenter then approached them personally and asked, as a favor, whether they would return the money, explaining that he was using his own funds and running short. In another, a secretary asked them to return it to the psychology department fund. In a third, they kept it. Subjects who had done the experimenter the personal favor rated him most positively.
The explanation is dissonance, and it is the same engine as chapters 3 and 13. I have gone out of my way for this person. Yet I do not like him. Those cannot both be comfortable, and only one of them can be revised after the fact. Bem's self-perception account gets there by a slightly different route: I lent him a rare book, and people lend rare books to people they think well of, therefore I must think well of him.
For the manipulator this is a genuinely useful piece of tradecraft, and it is counterintuitive enough that it is worth stating plainly: the way to convert a skeptic is not to give them something, which invites suspicion about your motive and may trigger reactance. It is to ask them for something small — advice, an introduction, a favor that flatters their competence — and then to be visibly grateful for it. The skeptic supplies the attitude change themselves, and because they supplied it, they do not experience it as having been influenced.
Watch for it in the sequence rather than the moment. Someone who asks a new acquaintance for a small favor early, thanks them disproportionately, and then asks again is running a ladder, and each rung is both an escalation of commitment and a manufacture of goodwill. Sales training teaches it. Political operators use it on hostile committee members. Recruiters for coercive groups use it on people who came to argue.
The way to keep your judgment intact is to separate the two questions the favor blurs together. Doing someone a small kindness is usually good and you should keep doing it. It is simply not evidence about their character, and the feeling that it is arrived after the fact.
Defense: The Gift With Strings: Neutralizing the Reciprocity Trap