Besides, the author claims that prehistoric sapiens may have committed a massive genocide, leading other homo species such as the Neanderthals into extinction. The book further argues that Homo sapiens can cooperate flexibly in large numbers, because it has a unique ability to believe in things existing purely in its own imagination, such as gods, nations, money and human rights. The author claims that all large scale human cooperation systems – including religions, political structures, trade networks and legal institutions – are ultimately based on fiction.[5]