Instead of defining all forms of social protest as social movements, Tilly uses a narrower definition. Conceptually, he argues that social movements share some elements with other forms of political contention such as coups, electoral campaigns, strikes, revolutions, and interest-group politics, but have their own distinct characteristics. He argues that the social movement developed in the West after 1750 and spread throughout the world through colonialism, trade and migration. Local populations are more likely to experiment with the social movement with democratization, and when successful, are more likely to incorporate it into their political struggles.