In 1730s Philadelphia, a rival lawmaker gave Benjamin Franklin a hard time. Franklin did not try to win the man over with flattery or gifts. He asked to borrow a book.

Franklin tells the story in his autobiography. A fellow member of the legislature, whom he describes as a man of fortune and education who would one day be influential, had taken a dislike to him. Franklin heard the man owned a very scarce and curious book. He wrote a note expressing his wish to read it and asking whether he might borrow it for a few days. The man sent it at once. Franklin returned it about a week later with a note of thanks.

The next time they met in the House, the man spoke to Franklin, which he had never done before, and with great civility. Franklin writes that the two became friends, and that the friendship lasted until the man died. He drew a maxim from it: He that has once done you a kindness will be more ready to do you another than he whom you yourself have obliged.

That is a good anecdote, but it is one man's account of his own life. Psychology has tested the idea since, and the results are more interesting than the anecdote.

What the research actually shows

In 1969, the psychologists Jon Jecker and David Landy ran an experiment on this, published as "Liking a person as a function of doing him a favour." Participants took part in a contest and won a small sum of money. They were then split into groups.

In one group, the experimenter approached them afterward and said he had paid the prize out of his own pocket. The funds were running low, and he asked whether they would do him a personal favor and give the money back. In a second group, a secretary made a similar request on behalf of the psychology department. A third group was not asked to return anything.

All the participants then rated how much they liked the experimenter. The group that had been asked for a personal favor by the experimenter himself rated him highest. The people who had given him something liked him more than the people who had received something from him.

That result runs against most people's instincts. We tend to assume that liking leads to helping, so that we do favors for people we like. The study suggests the arrow also points the other way, and that helping can lead to liking.

Why helping someone makes you like them

The usual explanation is cognitive dissonance, the term Leon Festinger introduced for the discomfort of holding two conflicting beliefs, or of acting in a way that clashes with how you see yourself. Suppose you did something generous for a person and you also think of that person as unpleasant. Those two facts sit badly together. Changing what you did is impossible, because you already did it. Changing your opinion of the person is easy, and it removes the tension.

A second mechanism works alongside it. Daryl Bem's self-perception theory proposes that we often infer our own attitudes by watching our own behavior, the way an outside observer would. If I lent this person my book, I must like them. Both accounts agree that the favor changes the favor-doer's view of the person they helped.

There is a plainer reason too. Giving usually feels good, and what feels good tends to attach itself to whoever was involved. You spent effort on this person and it cost you something, so they now matter to you a little more than they did before.

What this says about how we build friendships

Most of us treat closeness as a ledger. We worry about being a burden, so we avoid asking. We mean it kindly, but the effect is that the other person never gets the chance to invest in us. Many adult friendships stay shallow for this reason. Each side is courteous and careful, and neither has put anything into the other.

The Franklin effect points to a different model, in which closeness grows through mutual investment. A friend who has driven you to the airport, read your draft, or listened to a bad evening has a small stake in how your life turns out. That stake is part of what the friendship consists of.

There is a story that also gets shaped here. After they help you, the other person becomes a character in your life as well as an acquaintance. Their kindness becomes a scene they remember and you remember. Shared scenes like that are what friendships are made from.

Where the effect breaks down

It would be easy to turn this into a trick, and it is not one. A few limits are worth knowing.

The favor has to be small and reasonable. Jecker and Landy's request was modest. A large demand can read as an imposition, and then the dissonance resolves the other way: I did that grudging favor, so I must have been a pushover, and this person is exploiting me.

The helper has to have chosen to help. Dissonance only appears when someone feels they acted freely. If they feel coerced or guilt-tripped, they have an easy excuse ("I had no choice") and their opinion of you does not need to move.

Someone who has already been hurt by you will not be repaired this way. Franklin's rival was merely cool toward him. If you wronged a person, an apology and changed behavior come first. Asking for a favor on top of a real injury can look like another demand.

It cannot replace giving back. The effect works because the relationship is going somewhere. If you take repeatedly and never return anything, people will notice, and the goodwill will drain away. The point is to let people invest in you while you also invest in them.

There is also an ethical line. If you are asking for the favor mainly to manipulate how someone feels about you, that is a different act from asking because you could use the help. The honest version of the practice is to ask when you actually need something and to let people say no.

Your next moves

  • Pick one person you'd like to be closer to and make a small, real request today. Ask a coworker for a book or podcast recommendation, a neighbor to help you choose between two options, or an old friend for a short piece of advice. It should take them under five minutes.
  • Make the ask specific. "Could you look at the first paragraph of this email?" is easier to say yes to than "Can you help me with something?" A clear, bounded request respects the person's time.
  • Close the loop and say what it did for you. Within a week, tell them what you did with their help and thank them in concrete terms: "I used your suggestion and it saved me an hour." That turns their favor into something with a visible result.
  • Check your own ledger. Write down the names of two people who helped you recently and whom you never thanked properly. Message them today.
  • Reverse the direction by offering something small. If you want a friendship to be mutual, do a favor in return without being asked. A forwarded article or a quick introduction is enough.

A small note on writing it down

Most of the moments that deepen a relationship are small and disappear quickly: a borrowed book, a ride, ten minutes of advice. They are hardly ever recorded, so a year later we cannot say why we feel close to someone, only that we do. If you jot down the favor, who made it, and what they said, you keep the scene that the friendship grew from. Lore is built for noting a day like that in a few lines, so the small exchanges that form a friendship are still there when you look back. If that sounds useful, you can look at it at lore.lumenlabs.works. Either way, you could start by asking someone to lend you a book.