This document discusses sources of social change. It identifies three main sources: 1) Forces within a society like new inventions and loss of cultural practices; 2) Contact between societies, which can lead to diffusion of new ideas and practices, acculturation as an entire culture adopts new traits, and transculturation as individuals adopt a new culture; 3) Changes in the natural environment. All cultures experience both forces that encourage change and forces that encourage resisting change to maintain stability.