The Benjamin Franklin effect is a proposed psychological phenomenon, with an explanation of cognitive dissonance: a person who has already performed a favour for another is more likely to do another favor for the other than if they had receive a favour from that person. People reason that they help others because they like them, even if they do not, because their minds struggle to maintain logical consistency between their actions and perceptions. In other words, it is the result of one's concept of self coming under attack. Every person develops a persona, and that persona persists because inconsistencies in one's personal narrative get rewritten, redacted, and misinterpreted.
Benjamin Franklin, after whom the effect is named, explains how he dealt with the animosity of a rival legislator when he served in the Pennsylvania legislature in the 18th century. This was also mentioned in the book How to Win Friends and Influence People by Dale Carnegie (Part 5: Letters That Produced Miraculous Results). In this chapter, Carnegie analyses this example and describes how to appeal to someone with the term "do me a favor" as opposed to directly asking for something which does not offer the same feeling of importance to the recipient of the request.
Franklin asked a favour that pleased the other man - a favour that touched his vanity, a favour that gave him recognition, a favour that subtly expressed Franklin's admiration for his knowledge and achievements. This technique was used to turn a caustic enemy into a lifelong friend. This psychology of asking the other man to do you a favour, goes marching right on.
Please search for the specific part of the book for more detailed information.
