Drive-reduction theory proposes that a physiological need creates an aroused tension state—a drive—that motivates the organism to satisfy the need and thereby reduce the tension. The cycle restores internal balance.

Clark Hull developed the most systematic version of the theory. Hunger arises from a need for nutrients; the drive pushes the animal to seek food; eating reduces the drive and is therefore reinforcing. Thirst, temperature regulation, and other homeostatic systems follow the same logic. Behavior that successfully reduces drive becomes more likely in the future.

The theory accounts well for basic biological motives yet struggles with behaviors that increase rather than reduce arousal—curiosity, play, and the pursuit of excitement. It also underplays the role of external incentives and of cognitive expectations. Later motivation theories retained the idea of drive while adding incentive value, optimal arousal, and cognitive appraisals.

When a need builds and behavior is directed toward relieving it, drive-reduction theory still offers a clear and economical description.