Positive incentives motivate approach behavior; negative incentives motivate avoidance behavior. The strength of that behavior depends on the value or utility (usefulness) of the incentive. Value varies with incentive amount, contrast, quality, rate, an incentive-delay interval, and the internal state of a person. For temporal motivation theory, incentive value increases as the incentive-delay interval decreases. People may initially prefer a large delayed incentive. However, as a smaller alternative incentive becomes available sooner, people prefer it instead. They reverse their preferences, which accounts for procrastination. Extrinsically motivated behavior is coerced by external contingencies, such as money, while intrinsically motivated behavior is freely chosen. Intrinsic motivation is inherent in the behavior. Both extrinsic and intrinsic consequences motivate behavior although a person may orient more to one than another.