What is Classical Conditioning?
Classical conditioning is a process where our brain connects unrelated things or events, leading to automatic and involuntary responses. It helps us make associations between neutral stimuli and natural reflexes, which can have profound effects on our behavior and emotional reactions.
Classical conditioning is also known as Pavlovian Conditioning or Respondent conditioning. It is one of the learning theories and has a significant influence on behaviorism, a school of thought in psychology.
Pavlovian conditioning is a fascinating process of learning that occurs unconsciously. It involves forming associations between different stimuli to create a new learned response. Imagine a situation where you hear a particular sound, and it automatically triggers a specific reaction in you, even though the sound itself doesn’t naturally cause that response. That’s how classical conditioning works.
One of the most famous examples of classical conditioning is Pavlov’s experiment with dogs. He discovered that by pairing the sound of a tone (neutral stimulus) with the presentation of food (unconditioned stimulus), the dogs started salivating (unconditioned response). Eventually, just hearing the tone alone (conditioned stimulus) was enough to make the dogs salivate (conditioned response) even without the presence of food.
Classical conditioning has had a significant impact on the field of psychology, particularly behaviorism. It suggests that our environment plays a crucial role in shaping our behavior and learning. By associating stimuli together, we can create learned responses that guide our actions and reactions.
A Brief History of Classical Conditioning
Classical conditioning, also known as Pavlovian conditioning, originated from the pioneering work of Ivan P. Pavlov, a Russian psychologist, and scientist, in the late 19th and early 20th centuries. While studying salivary secretion in dogs, Pavlov noticed that the dogs began to salivate in response to stimuli associated with food, such as the sight of the food dish or the sound of approaching footsteps. This observation led him to explore the process of learning associations between stimuli.
In his famous experiment, Pavlov paired a neutral stimulus, such as the ringing of a bell, with the presentation of food. Over time, the dogs began to associate the bell with the food, and they started salivating in response to the bell alone, even without the presence of food. This demonstrated how a neutral stimulus could become a conditioned stimulus, eliciting a conditioned response.
Pavlov’s research revolutionized our understanding of learning and behavior. His work laid the foundation for classical conditioning, emphasizing the importance of associations and stimulus-response relationships in shaping our behavior and emotional responses. His findings were documented in his book, “Conditioned Reflexes,” published in 1927.
Pavlov’s contributions to classical conditioning have had a lasting impact on psychology and our understanding of how we learn and adapt to our environment. His work continues to be influential in the field of behaviorism and forms a fundamental concept in the study of learning processes.
Also Read: Top 20 Subfields/Branches of Psychology
Key Terms in Pavlovian Conditioning
The followings are the key phrases used in classical conditioning. In classical conditioning, these five terms represent the building blocks of learning associations between stimuli and responses.
Unconditioned Stimulus (US)
This refers to a stimulus that naturally and automatically triggers a response without any prior learning. It is something that elicits a reflexive or innate response. For example, in Pavlov’s experiment, the unconditioned stimulus was the presentation of food to the dogs, which naturally led to salivation.
Unconditioned Response (UR)
The unconditioned response is the innate or reflexive response that occurs naturally in response to the unconditioned stimulus. It is an automatic reaction that doesn’t require any learning. In Pavlov’s experiment, the unconditioned response was the dogs’ salivation in response to the food.
Neutral Stimulus (NS)
A neutral stimulus is a stimulus that, initially, does not elicit any particular response or reaction. It doesn’t have any inherent connection with the unconditioned response. In Pavlov’s experiment, the sound of a bell before conditioning was a neutral stimulus because it did not cause salivation in the dogs.
Conditioned Stimulus (CS)
A conditioned stimulus is a previously neutral stimulus that, through repeated association with the unconditioned stimulus, gains the ability to elicit a response similar to the unconditioned response.
In Pavlov’s experiment, after pairing the sound of the bell with the presentation of food multiple times, the bell became a conditioned stimulus that triggered salivation in the dogs.
Conditioned Response (CR)
The conditioned response is the learned response that occurs as a result of the conditioned stimulus. It is a response that is acquired through the association between the conditioned stimulus and the unconditioned response.
In Pavlov’s experiment, the conditioned response was the dogs’ salivation in response to the sound of the bell alone, without the presence of food.
How Classical Conditioning Works?
or, Stages in Pavlovian Conditioning, or Ivan Pavlov’s Experiment. There are three main steps in classical conditioning through which Pavlov experimented on the dog. Let’s understand these steps.
Before conditioning is the initial stage of classical conditioning where the unconditioned stimulus (US) is paired with the unconditioned response (UR). At this point, there is also a neutral stimulus that doesn’t elicit any response yet. For example, in Pavlov’s experiment, the smell of food acts as the unconditioned stimulus, which automatically triggers the unconditioned response of salivation.
During the before-conditioning phase, the neutral stimulus (such as a bell) is introduced, but it doesn’t have any effect or association with the desired response. The neutral stimulus does not elicit salivation in the dog.
The purpose of this phase is to establish a baseline and prepare for the conditioning process. The neutral stimulus will later become the conditioned stimulus (CS), eliciting a conditioned response (CR) through association with the unconditioned stimulus.
In Pavlov’s experiment, the neutral stimulus (bell) was presented alongside the unconditioned stimulus (food) during this phase. The goal was to create an association between the neutral stimulus and the unconditioned response of salivation. This lays the foundation for the subsequent conditioning process where the neutral stimulus becomes a conditioned stimulus that triggers salivation on its own.
During the conditioning phase of classical conditioning, the previously neutral stimulus is repeatedly paired with the unconditioned stimulus to create an association. Through this process, the once neutral stimulus becomes the conditioned stimulus (CS), which elicits a conditioned response (CR).
In this phase, the subject learns to associate the neutral stimulus with the unconditioned stimulus, leading to a change in their response. For example, if the sound of a whistle is paired multiple times with the smell of your favorite food, eventually the sound of the whistle alone will trigger a response similar to the natural response to the food.
The key idea is that the conditioned stimulus now carries meaning and can elicit a response on its own, even without the presence of the unconditioned stimulus. This association between the conditioned stimulus and the conditioned response is established through repeated pairings during the conditioning phase.
In Pavlov’s experiment, the neutral stimulus (bell) was consistently paired with the unconditioned stimulus (food) until the bell alone could trigger salivation in the dog. The dog learned to associate the sound of the bell with the arrival of food, leading to the formation of the conditioned response.
Overall, during the conditioning phase, the subject undergoes the process of learning and forming associations between the neutral stimulus and the unconditioned stimulus, ultimately resulting in the development of a conditioned response to the conditioned stimulus.
During the after-conditioning stage of classical conditioning, the conditioned stimulus (CS) alone is presented without the unconditioned stimulus (UCS), yet it still elicits a response. This response is known as the conditioned response (CR).
In this phase, the subject has learned the association between the conditioned stimulus and the unconditioned stimulus, and the conditioned stimulus alone is now sufficient to evoke the learned response. For example, if the sound of a whistle has been paired with the smell of food in earlier phases, hearing the whistle alone will now trigger the conditioned response, such as feeling hungry.
The key idea is that the conditioned stimulus has acquired the ability to produce the conditioned response through repeated pairings with the unconditioned stimulus. The subject has been trained to respond to the conditioned stimulus alone.
In Pavlov’s experiment, after the dog had learned to associate the sound of the bell (conditioned stimulus) with the arrival of food (unconditioned stimulus), the sound of the bell alone would elicit salivation in the dog (conditioned response).
Overall, during the after-conditioning stage, the subject demonstrates the conditioned response to the presentation of the conditioned stimulus alone, indicating that the classical conditioning process has been successfully completed.
Principles of Classical Conditioning Theory
Classical conditioning, a form of learning, involves several key principles that describe different phenomena associated with this process. Here are five essential principles explained in a unique and simple manner:
During acquisition, a neutral stimulus becomes associated with an unconditioned stimulus. Through repeated pairings, the neutral stimulus elicits a response, becoming a conditioned stimulus. Reinforcement can further strengthen the acquired response.
Extinction occurs when the conditioned response diminishes or disappears. This happens when the conditioned stimulus is no longer paired with the unconditioned stimulus. For example, if a bell no longer predicts food, the conditioned response of hunger will gradually fade away.
Sometimes, after a period of extinction, a previously learned response can spontaneously reemerge. Spontaneous recovery demonstrates that extinction does not erase conditioning completely. However, if the association is not reinforced, extinction will quickly return.
Stimulus generalization refers to the tendency of a conditioned stimulus to evoke similar responses to other stimuli that share similarities with the original stimulus. For instance, a dog conditioned to salivate at the sound of a specific bell may also respond to similar bell sounds.
Discrimination involves the ability to differentiate between a conditioned stimulus and other stimuli that have not been paired with an unconditioned stimulus. Animals or individuals can learn to respond only to specific stimuli while disregarding similar ones that lack the conditioning history.
Examples of Classical Conditioning
These examples illustrate how classical conditioning influences various aspects of human behavior, from food cravings and fear responses to addiction cues.
Example 1: Food Craving
Think of a mouth-watering food smell that triggers a pleasant memory, like the aroma of a fresh, luscious orange pickle. Your mouth may start to water. In this example, the food smell represents the unconditioned stimulus (UCS) that naturally elicits salivation, which is the unconditioned response (UCR). Now, when you hear the name of your favorite food, such as “Suntala Sadheko,” it has become the conditioned stimulus (CS), and your salivation in response to that name becomes the conditioned response (CR).
Example 2: Fear Response
Imagine someone accidentally puffs on your eyes, causing you to blink. The next time you see that person, even without any puffing, you still blink involuntarily. This demonstrates classical conditioning in the development of a fear response. The initial puffing stimulus is the UCS, eliciting the fear response (UCR) of blinking. Over time, the person becomes the conditioned stimulus (CS), and your blink in their presence becomes the conditioned response (CR).
Example 3: Addiction Cues
Cue reactivity theory explains how cues associated with drug use can trigger cravings in addicted individuals. Consider a person who associates meeting friends or going to a specific place (e.g., a pub) with the rewarding effects of nicotine. These cues become smoking-related cues. Initially, nicotine itself is the UCS, causing pleasure as the UCR due to increased dopamine levels.
The neutral stimuli (NS) associated with smoking, such as meeting friends or going to the pub, become conditioned stimuli (CS) through repeated pairings. They can then produce the conditioned response (CR) of craving and physiological arousal, even without nicotine present.
Applications of Classical Conditioning
Classical conditioning has various practical applications in different fields. Here are three unique applications of Pavlovian conditioning. These examples demonstrate how classical conditioning principles are utilized in real-world applications.
Advertising and Marketing
Classical conditioning plays a significant role in advertising and marketing strategies to create positive associations with products or brands. Advertisers often pair their products with pleasant or desirable stimuli, such as attractive models, catchy jingles, or beautiful landscapes.
By repeatedly presenting these stimuli alongside their products, they aim to condition consumers to associate positive emotions or desires with their brand. For example, a soda advertisement may consistently show people having a great time at parties while enjoying the drink. Over time, seeing the product can evoke positive feelings and increase the likelihood of purchasing it.
Classical conditioning techniques are also used in the treatment of phobias. Phobias are intense and irrational fears of specific objects or situations. Therapists employ a process called systematic desensitization to help individuals overcome their phobias.
By gradually exposing patients to the feared object or situation in a controlled and safe environment, while simultaneously teaching relaxation techniques, therapists aim to replace the fear response with relaxation. Over time, through repeated exposure without negative consequences, the conditioned fear response is replaced with a more relaxed and neutral response.
Classical conditioning is widely employed in animal training, whether it’s for household pets or working animals. Trainers use positive reinforcement by pairing desired behaviors with rewards, such as treats or praise.
For example, when training a dog to sit on command, the trainer pairs the command (“sit”) with a treat, leading the dog to associate the command with the reward. Through repeated pairings, the dog learns to sit in response to the command. Classical conditioning is also used in training animals for specific tasks, such as guide dogs for the visually impaired or search and rescue dogs.
Criticisms of Classical Conditioning
Critics argue that classical conditioning theory overlooks individuality and free will, as it assumes the behavior is solely determined by conditioned responses. They claim it fails to predict human behavior accurately, as people may not always act on the associations formed.
Moreover, multiple factors can influence outcomes, and individuals can choose not to respond to conditioned stimuli. The deterministic nature of classical conditioning undermines human uniqueness and the freedom to shape one’s own destiny.
However, classical conditioning remains relevant in psychology, with applications in dog training, phobia treatment, and creating positive classroom environments. Despite its limitations, the approach continues to captivate researchers and contribute to our understanding of behavior.
Difference Between Classical Conditioning and Operant Conditioning
Classical conditioning and operant conditioning are two distinct forms of learning, each with its own pioneers, principles, and applications.
Classical conditioning, discovered by Ivan Pavlov, focuses on the association between stimuli. It involves pairing a neutral stimulus with an unconditioned stimulus to elicit a conditioned response. For example, Pavlov’s famous experiment with dogs pairing a bell (neutral stimulus) with food (unconditioned stimulus) to elicit salivation (conditioned response). Classical conditioning is used in advertising, phobia treatment, and animal training.
Operant conditioning, pioneered by B.F. Skinner centers around the relationship between behavior and its consequences. It involves reinforcing desired behaviors and punishing or ignoring undesired behaviors. Skinner’s Skinner Box experiments demonstrated this. Operant conditioning is employed in behavior modification, education, and animal training to shape and reinforce behaviors.
While classical conditioning focuses on involuntary responses, operant conditioning deals with voluntary actions and their consequences. Understanding these differences helps in applying the appropriate learning principles to achieve desired behavioral outcomes.
- Wolpe J, Plaud JJ. Pavlov’s contributions to behavior therapy. The obvious and not-so-obvious. Am Psychol. 1997;52(9):966-72.
- Bremner, J. D., Southwick, S. M., Johnson, D. R., Yehuda, R., & Charney, D. S. (1993). Childhood physical abuse and combat-related posttraumatic stress disorder in Vietnam veterans. The American Journal of Psychiatry.
- Brewer, W. F. (1974). There is no convincing evidence for operant or classical conditioning in adult humans.
- Carter, B. L., & Tiffany, S. T. (1999). Meta‐analysis of cue‐reactivity in addiction research. Addiction, 94(3), 327-340.
- Lin J-Y, et al. (2014). Conditioned taste aversion, drugs of abuse, and palatability. DOI:
- Rehman I, et al. (2019). Classical conditioning.
- Windholz G. Pavlov on the conditioned reflex method and its limitations. Am J Psychol. 1995;108(4):575-88.
- Holland JG. Behaviorism: Part of the problem or part of the solution. J Appl Behav Anal. 1978;11(1):163-74. doi:10.1901/jaba.1978.11-163
- Rouleau N, Karbowski LM, Persinger MA. Experimental evidence of classical conditioning and microscopic engrams in an electroconductive material. PLoS ONE. 2016;11(10):e0165269. doi:10.1371/journal.pone.0165269
- Goldman, Jason G. “What is Classical Conditioning? (And Why Does it Matter?)” Scientific American, 11 January 2012.
- The Nobel Prize. Ivan Pavlov biographical.