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A Brief History of Classical Conditioning: Basic Concepts and Authors

What is Behaviorism?

Behaviorism is a theory of learning in psychology that proposes that behaviors (actions) are acquired through the interaction with the environment. This process is called conditioning.

There are two main types of conditioning, classical conditioning, and operant conditioning. In this article, we are going to talk about classical conditioning

Now, if behavior comes from interaction with the environment, then what does behaviorism have to say about the mind?

The truth is, different authors of behaviorism have different postures about things that are not part of the environment, such as the mind and consciousness. Some behaviorist authors reject the concept, others accept it, and some others do not deny their existence but consider them a sort of “black box” that should not be studied because it cannot be studied objectively. Usually, the authors of Classical Conditioning reject the idea of a mind, or at least consider it useless to study behavior.


Behaviorism Origins' Context

There are a few things we have to consider, what was happening in the world and the field of psychology when behaviorism emerged?

  • Before World War I, psychology justified its activities in practical terms, that is, it had become an objective science that had concentrated on understanding and predicting human behavior.
  • Behaviorism was born in the United States from functionalism and animal psychology.
  • One of the main contributions of functionalism was to provide the principles to study child and animal psychology, that is, it expanded the object of study of psychology.
  • Behaviorism is an extension of views and methods from animal to human psychology.

The Precursor of Classical Conditioning: Thorndike

He is a precursor of behaviorism, as he initiated the transition from functionalism to behaviorism. It was with the reading of psychology texts that pushed Thorndike into psychology and his entry into Harvard in 1897 where he began his research on animal behavior. He put the animals in labyrinths to observe their behavior (example: a cat). From this, he described learning in terms of:

  • Trial and error
  • Fortuitous occurrences.
  • Associations between events.
  • Repetition of an experience.

He observed behavior, from the laboratory to uncontrolled natural environments to have an objective view of behavior. Studied traits from animal behavior.

He left Harvard and moved to Columbia University. Many concepts he learned at Harvard he developed at Columbia, focusing his study on actions that result from the experience learned, not instinctive or reflective behavior, thus he began to separate himself from functionalism.

Thorndike claimed that animals learned through:

  • Trial and error
  • Reward -punishment

Animals associate, but do not associate ideas, the effective part of the association is a direct link between the situation and the impulse.

Despite criticism, Thorndike developed a theory of learning that encompassed both animals and humans. He argued that the purpose of psychology should be the control of behavior. He proposed three major laws that determine learning:

  • Law of readiness: When a subject is ready to learn, it is likely that better results are achieved.
  • Law of effect: The results of behavior closely followed by satisfying consequences were most likely to develop reoccurring patterns in response to the same stimulus, likely to disappear when faced with negative outcomes.
  • Law of exercise: The connection between a stimulus and a response can be strengthened or weakened. This connection can be strengthened by practicing hard and often, or it can be weakened by discontinuing the practice.

In 1930, Thorndike revised these laws, he withdrew the law of exercise and revised the law of effect, arguing that responses that undesired outcomes did not weaken the response as much as satisfying outcomes strengthen the response.

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Just as animal learning is automatic, that is, it is not mediated by awareness of the contingency between response and reward. He argues that human learning is also unconscious, since a person can learn a response without being conscious.

It recognizes a problem in behaviorism about explaining human behavior without reference to meaning.


Ivan Pavlov: from Physiology to Conditioning

Ivan Petrovich Pavlov, a Russian physiologist, had begun his research work to study glandular and nervous factors in the digestive process, work for which he would be awarded the Nobel Prize in 1904.

Pavlov is the father of classical conditioning, which is a stimulus response or learning model by associations. It consists of exposition to a natural stimulus and connecting it with a second stimulus to generate a response that does not occur naturally.

From an Unconditioned Stimulus (UCS), a.k.a. a natural stimulus, a response is generated, an Unconditioned Response (UCR). Then, they pair this UCS with a second, neutral stimulus (NS) to generate a conditioned response (CR), that is, a response that would not occur naturally. The NS thus becomes a Conditioned Stimulus (CS), a stimulus that causes a response that the UCS caused originally.

Within conditioning, we can find these aspects:

  • Intensity: force with which a response occurs.
  • Repertoire: total responses.
  • Reinforcement: Stimulus that causes a modification in the probability of the emission of a behavior.
  • Latency: Time elapsed between the presentation of the stimulus and the emission of the response.
  • Threshold: minimum intensity that requires a stimulus to generate a response

Fundamental principles according to Pavlov:

  • Acquisition: The process by which a response is incorporated into an organism's repertoire.
  • Extinction: Loss of conditioning because of non-reinforcement of a response
  • Spontaneous recovery: unexplained appearance of a response that had been previously extinguished.
  • Stimulus generalization: a stimulus like the CS causes the same responses as the real CS. The greater the similarity, the greater the effect.
  • Discrimination: It is the ability of the organism to differentiate a series of similar stimuli.

This theory rejects the concept of mind for an objective and materialistic conception. The whole mechanism of thought consists in the elaboration of elementary associations and the subsequent formation of associational chains. Pavlov tried to replace psychology with physiology and replace references to the mind with references to the brain.

One of the problems with this theory is attempting to draw a dividing line between intelligence and mind, and reaction to external stimuli. Because his experiments were done on animals and not on humans, and most animals had no high intelligence, but higher animals, such as humans, did, it became hard to study similarities in both.


John B. Watson: A Radical Approach

For John B. Watson, the problem of mind and consciousness, the greatest criticism of behaviorism, was something that did not apply to his interests since he sought an objective and materialistic method to understand the behavior of animals and not higher beings.

He concluded that the concept of mind had lost value to both animal and human psychology. He thought that if psychology wanted to become a scientific discipline, it should get rid of consciousness, and should opt for public, quantifiable, observable studies and experimentation, as other natural scientists did.

Watson argued that psychology should move away from philosophy and reorient itself to biology, that is, to take observable responses and environmental stimuli as the basic elements of psychological research.

To Watson, Behavior can be predicted in terms of stimuli and response. Thought does not involve the brain, he considered it a distraction. He said that there are no processes initiated in the central nervous system.


Hergenhahn, B. R., Henley, T. B. (2013). An Introduction to the History of Psychology. Belmont, Wadstworth.

© 2022 Hiromi Kurihara

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