ABSTRACT
In everyday use the word “reward” describes an event that produces a pleasant or positive affective experience. Among behavior scientists, reward is often used to describe an event that increases the probability or rate of a behavior when the event is contingent on the behavior. In this usage reward is a synonym of reinforcement. At best these common usages create ambiguity. At worst the two meanings of reward are con ated, leading to the assumption that reinforcement is always the result of positive affect produced by rewarding events. Although reward certainly in uences behavior, its in uence is not as straightforward as is often assumed, nor is reward the only reinforcement process that can in uence behavior.
