Associations of people sharing a common interest have been around for as long as human beings have tended to socially interact outside the realms of their immediate families or clans. All manner of social interactions between clans led to the development of socio-political systems based on agreed norms or rules. These socio-political structures were maintained by a variety of governance structures, such as the institutions of modern day social-democracies. One can also argue that political governance structures were created or evolved to serve societal interests and the issues of how societies govern themselves, and what system of governance suited society is what inspired political thought from the days of early Greek philosophers.