The main thesis of Nonzero is that social complexity of human culture has been increasing since the dawn of man and will continue to do so until forever. Wright argues that non-zero sum games are the culprit: societies get more complex (moving from tribes of hunter gatherers to mutli-trillion dollar global economy) because in order to play ever more lucrative non-zero sum games with an increasing number of people, that?s the way it has to be. It makes a lot of sense.