Drive Reduction Theory

Drive Reduction Theory was developed by the psychologist Clark Hull in 1943, as the first theory for motivation. It was one of the popular theories of motivation during the 1940s and the 50s, not only as a theory to explain motivation, but also learning and behavior. Hull’s attempt to explain all behavior was assisted by his collaborator Kenneth Spence.


The theory states that

Reduction of the drive is a major cause of learning and behavior.

Although it was the dominant force in the world of psychology where theorists were trying to come up with ideas to explain behavior, it is largely ignored today. However, it can still be highly useful for students in order to understand the effects of his work on psychology.

Understanding Hull’s Drive Reduction Theory

Hull believed that human body continuously tries to maintain a state of balance, known as homeostasis. And, behavior was an essential factor for an organism to maintain this state of equilibrium.

This idea later led him to propose the Drive Reduction Theory. He suggested that all motivation arises as a result of the need to fulfill certain things. The term drive refers to

The state of tension or arousal caused by biological or physiological needs.

For example: hunger, thirst and sex are examples of primary drives, something that is extremely vital.

Likewise, drives learned by conditioning are secondary drives (money).

Drives aren’t necessarily in a singular pattern. When an organism is aroused with multiple needs at once, the condition is called multiple drives. This has an impact on earnings.

In psychological vernacular,

“Generalized conditioned reinforce has greater learned reward value than a simple conditioned reinforce.”

In simple terms, multiple drives are followed by quicker learning than a singular drive.

Hull believed that every human behavior could be explained by conditioning and reinforcement. Reduction of the drive causes satisfaction, which then acts as a reinforcement for that behavior. Thus, the behavior is most likely to be repeated again when the reinforcement increases, meaning, the same need is aroused in the future.

Hull explained that

In order to survive in its environment, an organism must behave in ways that meet these survival needs. When survival is in jeopardy, the organism is in a state of need (when the biological requirements for survival are not being met) so the organism behaves in a fashion to reduce that need.

This is nothing but the explanation of the S-R (Stimulus-Response) relationship. When response caused by the stimulus leads to satisfaction or reduction of a certain need, the chances of the same stimulus leading to the same response is high.

Critical Evaluation

  • The first major issue with Hull’s reduction theory is that it fails to explain how drive is also reinforced by secondary reinforcers. For example, money itself is not responsible for the fulfillment of our psychological and biological needs, but it does assist in regular drive reduction in the form of a paycheck.
  • The theory also fails to explain the reason behind humans and other animals deliberately increasing tension by exploring their environments, even if they are not facing the drive of hunger or thirst.
  • Another limitation of the theory is seen while trying to explain pleasure-seeking behaviors. These behaviors, in fact, go completely in contrast to the theory’s general directives. For example, a person leaves the comfort of his home to explore the Amazon rainforest. Despite the lack of any biological or psychological drive, the individual puts in a lot of effort to go there.

Judson Brown has made an attempt to explain this circumstance.

the sensory consequences of most responses are practically never intense enough to provide increments to the drive level.

It makes sense to believe that the psychological drive is the most powerful one, as the individual’s first instinct will be to gather food and water no matter where he is. Only then, will he go on to reduce other needs or drives.

Mathematico Deductive Theory of Behavior

Hull even came up with a mathematical formula in order to understand and explain a complex matter that human behavior is. He named it Mathematico Deductive Theory of Behavior

The formula he developed is:

sER = (V x D x K x J x sHr) – (sIr + Ir) +/- sOr

sEr: Excitatory potential, or the likelihood that an organism will produce a response (r) to a stimulus (s)

sHr: Habit strength, established by the number of previous conditioning

D: Drive strength, determined by the amount of biological deprivation

K: Incentive motivation, or the size or magnitude of the goal

J: The delay before the organism is allowed to seek reinforcement

lr: Reactive inhibition, or fatigue

slr: Conditioned inhibition, caused by previous lack of reinforcement

sLr: Reaction threshold, the smallest amount of reinforcement that will produce learning

sOr: Random error