Neofunctionalism describes and explains the process of regional integration with reference to how causal factors interact with one another. According to Ernst Haas integration was the process whereby political actors in several distinct national settings are persuaded to shift their loyalties and activities towards a new center whose institutions possess or demand jurisdiction over the pre-existing national states. It attempts to predict political outcomes; it appears to predict what it implicitly desires. According to Neo functionalism, certain functions are best performed at a level higher than the nation state. Supranational cooperation requires both a supranational authority and some kind of public allegiance to that level in order for that authority to be effectively exerted. Once one function has been allocated to a supranational body this unleashes certain pressures that create an impetus for more functions to be ceded to that level- spillover. Spillover takes a number of forms. There is a spillover of functions as the creation of one supranational function makes it more effective for another function to also be performed at the supranational level. As functions are delegated to the supranational level so political activity starts to locate that level creating a new political community with political allegiance for that level. All these factors combine to create spiral like pressures for more and more functions to be delegated to the supranational level and for political allegiances to be refocused to the supranational level.
Neofunctionalism was an attempt by theorists like Jeffery Alexander among others to revive the stronger tenets of structural functionalism by synthesizing portions of structural functionalism with other theories. The social order between individuals and organizations of society has to share norms and values in order for society to function properly and when social change occurs it is not rapid instead it is regulated which ensures adaption properly and that each interdependent part of the structure serves to ensure that social order continues and society functions properly. Neo-functionalism highlighted the interactional patterning of the elements that constitute society attended to both action and order, understood integration as a possibility rather than as fact and traced the process of social change that resulted from differentiation within action systems.