Emile Durkheim distinguished between mechanical solidarity in rural societies with little division of labor, where solidarity is based on likeness, and organic solidarity in urban areas with a complex division of labor, where solidarity comes from interdependence. Durkheim believed a society's level of social solidarity depended on its division of labor, with mechanical solidarity in predomintantly rural societies and organic solidarity in highly diverse and specialized urban areas. His ideas formed a theoretical foundation for studying differences between rural communities and urban social structure.