While I have implicitly understood this rule for most of life, it wasn’t until I read the book, Influence: The Psychology of Persuasion by Robert Cialdini, about 5 years ago or so. While I recommend the book as a whole, it’s the very first chapter, Reciprocation, that’s the real game-changer. This “rule” is probably the single most important factor to any success I have had thus far. I highly recommend reading, studying, and practicing it frequently. More on this in a future post. If you just want to read chapter 2 you can do so here.