Drive theory, also known as drive reduction theory, is a psychological theory of motivation and learning generally attributed to Clark Hull, a psychologist at Yale University from 1929 to 1952. Drive theory states that human beings typically experience biological or psychological drives or needs, and that much of human behavior occurs as an effort to satisfy those needs and reduce the potency of biological or psychological drives. These drives can include basic physical needs, such as thirst, hunger, or the desire for sex, or they can also include psychological needs, such as the need for companionship. Hull believed that much of the learning process depends on drive reduction. Human beings first recognize a need, then take action to fulfill the need, then learn, through behavioral conditioning, how that need can be satisfied in the future.
All human beings, and many other organisms, have basic physical and psychological needs. Most people acknowledge the human physical needs for food, water, clothing, shelter, and warmth. Psychological needs typically include the need to feel loved, to feel accepted by a community, to enjoy companionship, to engage in creative expression, and to feel safe. Psychological and physical needs can occur simultaneously in the same person, working together to create a singular drive. One example of this could be the drive for physical and sexual contact, integrated with the drive for love, that drives many people to seek out long-term romantic partners.
Hull's drive theory states that, when an organism experiences a physical or psychological drive, and is aware and attentive to it, that organism will take action to reduce the drive's strength by fulfilling the need. For example, when a person feels hungry, he is experiencing a biological drive for food. Seeking and eating food reduces that drive by relieving the hunger. Often, the drive reduction occurs on a temporary basis only. The need may reappear, and, when it does, drive theory states that renewed action will be necessary to fulfill the need again.
Hull went on to postulate that this pattern of behavior, in which a need stimulates an action intended to fulfill the need, is a basic component of the learning process. When a person experiences a need and takes successful action to fill that need, he is more likely to repeat the same action the next time he feels the same need. Once the same need-fulfilling action has been successfully repeated a few times, most organisms learn, through the process known as behavioral conditioning, that that action will always lead to the same need-fulfilling consequences. If, by some chance, a formerly successful need-fulfilling action loses its efficacy, then drive theory states that the organism will seek an alternative action to fulfill the need.