"The singleton hypothesis is that Earth-originating intelligent life will (eventually) form a singleton. It is an open question whether the singleton hypothesis is true. My own opinion is that it is more likely true than not. Historically, we have seen an overarching trend towards the emergence of higher levels of social organization, from hunter-gatherer bands, to chiefdoms, city-states, nation states, and now multinational organizations, regional alliances, various international governance structures, and other aspects of globalization. Extrapolation of this trend points to the creation of a singleton."