Incentive theory, or the "pull theory" of motivation, suggests that external rewards primarily drive behavior. Individuals are motivated to engage in activities when they anticipate a desirable outcome. This is why people often work hard for promotions or study intensively to achieve high grades. These incentives can be tangible, physical rewards such as money or promotions, or intangible, non-physical rewards like praise and social recognition.

The theory differentiates between intrinsic and extrinsic motivation. Intrinsic motivation refers to engaging in activities for personal satisfaction, such as learning a new language, simply because it is fascinating. On the other hand, extrinsic motivation arises from a desire to gain external rewards, like studying to earn high grades or working to receive a bonus.

An example of the extrinsic theory concept is the overjustification effect, which occurs when external rewards reduce intrinsic motivation. In a well-known experiment, children who drew pictures expecting a reward later showed less interest in drawing for its own sake. This suggests that introducing external rewards can shift attention away from the inherent pleasure of the activity.

Conversely, the contrast effect, another example of the extrinsic theory concept, highlights how removing an expected reward can diminish motivation. For example, a rat navigating a maze might lose interest if it no longer finds cheese at the end. This sudden absence of reward creates a stark contrast, demotivating the individual from continuing the behavior.

In pull theory, behavior is often driven by the anticipation of a reward. For instance, even if they aren't hungry, someone may eat dessert because of its appealing flavor. The theory also suggests that learned associations with these stimuli can enhance their pull, reinforcing certain behaviors. As a result, human motivation is a complex interplay between internal needs and external incentives.