This is an excellent question! The social theories of Peter Berger make this point very clear. Let me lead you through his social theory.
First, according to Berger, all societies are constructed by people. He calls this the social construction of reality.
Second, within these socially constructed realities, there are things that are accepted and acceptable and things that are not. If people break the socially accepted norms, then they will be ostracized in some way. If they comply, then they will fit in. There is where the idea of roles come into play. When people play the proper roles of society, then they become socialized into their cultural setting.
Third, those in power usually create these roles to benefit themselves. Berger calls this ideology. When everything is going as planned by those in power there is what Berger calls institutionalization.