Drive reduction theory, also known as drive reduction theory, is a motivational theory that proposes that organisms are motivated to act to reduce internal tension caused by unmet needs. It suggests that behaviors are learned when they reduce biological needs, such as hunger and thirst. This theory, developed by Clark Hull and Kenneth Spence, explains motivation as a process of reducing tension created by physiological needs, but it has been criticized for failing to explain behaviors that do not reduce needs, such as pleasure seeking and exploration.