The Science of Likability: 27 Studies to Master Charisma, Attract Friends, Captivate People, and Take Advantage of Human Psychology

Life is harsh and people competitive. We naturally must look after our own interests. We also want to feel that we are independent, doing our own bidding. That is why when others try to persuade or change us, we become defensive and resistant. To give in challenges our need to feel autonomous. That is why to get people to move from their defensive

Ben Franklin effect tells us that one favor begets more favors and, over time, small favors beget larger ones.

It teaches us that our best option when dealing with other people we cannot trust entirely is to reciprocate their choices. Seeing as we can rarely place full trust in anyone, especially if they stand to gain by screwing us over, we lean toward tit for tat. In general, we view this as fair and just.