The behavioral approach to understanding motivation deals with drives, both learned and unlearned, and with incentives.
Drive theory. Drive theory involves the concepts of unlearned (or primary) drives, drive reduction, and learned (secondary) drives. It is based on the fact that all living organisms have physiological needs that must be satisfied for survival (for example, the need for food, water, sleep, and so forth) to maintain a state of homeostasis, that is, a steady internal state.
Disruption of an organism's homeostatic state causes a state of tension (arousal) called an unlearned, or primary, drive. If the aroused state has been created by hunger, it is called a hunger drive, and the drive can be reduced by food. Drive reduction moves toward the re‐establishment of homeostasis. Drives, then, may be thought of as the consequence of a physiological need, which an organism is impelled to reduce or eliminate. Clark Hull, a learning theorist, developed an equation to show how learning and drive are related.
Drives may also be learned, or secondary. Fear (or anxiety), for example, is often considered a secondary drive that can be learned through either classical or operant conditioning. In Neal Miller's well‐known operant conditioning experiment, a rat was placed in a black box and then given a mild electrical shock. Eventually, the rat learned to react to the experience of being put in a black box (with no shock given) with the response of turning a wheel to escape. In this case, the black box is said to have elicited the learned drive of fear. Among other drives considered by some theorists to be learned are the need for affiliation (that is, to belong, to have companionship), the need for security (money), and the need for achievement.
Incentive motivation. Theories of incentive motivation contend that external stimuli can motivate behavior. Humans (and other animals) can learn to value external stimuli (for example, the first prize in a track meet for a human and a pat on the head for a dog) and will work to get them. Incentive motivation is sometimes called “pull” motivation because incentives are said to “pull” in contrast with the “push” associated with drives.
Kenneth Spence, well known for his work in incentive motivation, suggested that the incentive value of the reward strengthens the response. (One would run faster for a reward of $100 than for one of $1.)