In this book I present a study about the human economic relations, at the light of what I believe to be their main factors: selfishness, altruism in its various forms and then the aptitude to cooperation and to exchange. After a short comparison between social insects and human societies, I identify a peculiar instrument of human relations: money. I explain why money cannot be considered neutral and how it is the basis of the functioning of an economic system, often determining its behaviors and results.