In order for a relationship to be successful, both partners need to feel invested. The more time, effort, or work you put towards a person, the more you’re personally investing in them and the more you want it to work out. The Ben Franklin effect, named after the Scientist Benjamin Frankin, is a psychological phenomenon which states that “a person who has done or completed a favor for someone is more likely to do another favor for that person than they would be if they had received a favor from that person”.
“Having heard that he had in his library a certain very scarce and curious book, I wrote a note to him, expressing my desire of perusing that book, and requesting he would do me the favour of lending it to me for a few days. He sent it immediately, and I return’d it in about a week with another note, expressing strongly my sense of the favour. When we next met in the House, he spoke to me (which he had never done before), and with great civility; and he ever after manifested a readiness to serve me on all occasions, so that we became great friends, and our friendship continued to his death.”
See the video below to see how beautifully they have explained the Ben Franklin effect.