There is a new field called experimental economics. Classic economic theory is based on the assumption that financially we all act selfishly to maximize our own benefits. The new field studies in what ways that assumption is false. One of their most interesting experiments involving having two strangers play a game. The rules are explained to them both, but they never meet or directly interact. They have the chance to be given a total of 100 dollars. Player A must make a proposal of how to split that money. And player B has the option of accepting or rejecting A’s offer. If he accepts it, they get the money according to the proposal. If he rejects it, neither get anything. There is only one round. After B accepts or rejects the offer the game is over. Classic economic theory suggests that A will propose that he get $99 and B get $1. And B will accept, because $1 is better than nothing.
But their experiments showed that in fact, on average, A will propose a split of 55/45, with him getting the $55 of course. We all try to be mostly fair, only taking the extra $5 due us based on our own undeniable uniqueness.