A motive is something that causes a person to act in a certain way or do a certain thing. It can be a need, desire, incentive, or reason for doing something. In the context of crime, a motive is often used to understand why a suspect committed a crime. A motive can also refer to a recurrent phrase or figure that is developed through the course of a musical composition. In art, literature, and music, a motive is a motif. In physics, motive refers to something that causes or tends to cause motion. In social settings, motive can refer to the activity that members of a social group will be participating in on a particular occasion.