Drive reduction theory is a major theory of motivation in the behaviorist learning theory tradition, developed by Clark Hull in 1943). The theory suggests that behavior is motivated by the need to reduce physiological imbalances or "drives". "Drive" is defined as motivation that arises due to a psychological or physiological need, and it works as an internal stimulus that motivates an individual to sate the drive). According to the theory, when humans experience a physiological or psychological need, such as reducing hunger or boredom, they feel a drive to satisfy that need). Drive reduction theory is based on the concept of homeostasis, which is the idea that the body actively works to maintain a state of balance or equilibrium. As soon as there is an unmet need within the body, a person starts behaving in a manner that allows them to address this need, reduce the drive, and achieve a state of balance.

Drive reduction theory distinguishes between primary drives, which are innate drives such as thirst, hunger, and sex, and secondary drives, which are learned by conditioning, such as money). However, there are also complications to drive reduction theory caused by so-called "pleasure-seeking" behaviors, which seem to be contradictory to the theorys precepts). For example, why would an individual actively seek out more stimulation if they are already in a state of relaxation and fulfillment? ).

While drive reduction theory was once a dominant theory in psychology, it is largely ignored today with the development of newer theories. However, it is still useful to understand how earlier researchers sought to explain human motivation.