Classical Conditioning

Medically reviewed by Julie Dodson, MA
Updated July 8, 2024by BetterHelp Editorial Team

Classical conditioning, or Pavlovian conditioning, is a form of learning developed by the Russian physiologist, Ivan Pavlov in the early 20th century. This form of psychology is now known as behaviorism, which is based on the idea that the environment can shape behavior and that all learning happens through interactions with your environment.

Many factors influence our behavior

Classical conditioning: Pavlov's dogs

If you have never heard of Pavlov, then you may not know about Pavlov's dogs. These canines were laboratory animals used in testing his theory. In the late 1800s, Pavlov was working with dogs to determine why dogs salivated when being fed, and he accidentally discovered the classical conditioning response. Pavlov hypothesized that the canines would salivate when they were given their food, and a small tube was placed into their cheek to measure it. However, it was found that the dogs began to drool before they got their food. They began to salivate when they heard the footsteps of the person bringing them the food.

After recording this reaction many times, Pavlov decided to try to condition the dogs to another stimulus and see if the salivating response could be learned. He used a clicking metronome to see if the dogs would salivate when hearing it, and, of course, they did not. Then, Pavlov introduced the metronome clicking every time the dogs were fed for several weeks. He once again introduced the metronome clicking to see if the dogs would start salivating, and they did, proving that his conditioning response worked. He went on to use other stimuli to see if he could condition the dogs to other noises, such as the ringing of a bell, which worked just as well as the footsteps and metronome clicking.

Today, teachers often refer to Pavlov’s experiment with the dog and the sound of a bell when teaching the principles of classical conditioning (Pavlovian conditioning). Before conditioning occurs, at the start of the experiment, a bowl of food (unconditioned stimulus) causes the dog to salivate (unconditioned response). Meanwhile, the sound of a bell (neutral stimulus) evokes no response from the dog. During conditioning, the sound of a bell combined with food causes the dog to salivate (unconditioned response). After the conditioning, the sound of the bell (conditioned stimulus) causes the dog to salivate (conditioned response). This peer reviewed experiment is a simple example that educators can use to teach the principles of classical conditioning.

3 stages of classical conditioning

There are three stages of classical conditioning:

  • Before conditioning, the unconditioned stimulus produces an unconditioned response in a person. In other words, something in the environment produces an automatic response that is unlearned (unconditioned) and is a natural response. For instance, the smell of vanilla may make you feel hungry, or the sound of birds singing may make you happy.
  • During conditioning, a stimulus that does not produce a response is associated with an unconditioned stimulus, making it the conditioned stimulus. For example, the smell of a certain perfume may be associated with a certain person who typically wears that scent.
  • After conditioning, the conditioned stimulus is associated with the unconditioned stimulus and creates a new conditioned response.

5 principles of classical conditioning

There are five key principles of classical conditioning, which include acquisition, extinction, spontaneous recovery, stimulus generalization, and stimulus discrimination.

  • Acquisition is the first stage of learning, when the response is established and strengthened. During this step, a previously neutral stimulus is repeatedly combined with an unconditioned stimulus. This causes an individual to associate the two and begin to show behavior in response to the stimulus.
  • Extinction is the stage when the episodes of a conditioned response start to decrease or disappear. This typically happens when a conditioned stimulus is no longer linked to an unconditioned stimulus. If you continue to remove the conditioned stimulus from the unconditioned stimulus, the response will disappear completely.
  • Spontaneous recovery happens on its own for no obvious reason. This is the learned response suddenly coming back after a period of extinction. For instance, if you have trained a dog to drool when you ring a bell and then stop reinforcing that behavior, the response eventually becomes extinct. However, if after some time you ring the bell and the dog drools, that is spontaneous recovery.
  • Stimulus generalization is when the conditioned stimulus causes a similar response after the original response has been established. In other words, the dog you have trained to drool when you ring a bell may also drool when he hears a similar sound, such as a telephone or a doorbell.
  • Stimulus discrimination is the ability to separate a conditioned stimulus from other stimuli that have not been linked to the unconditioned stimulus. For instance, if the dog you trained to drool at the sound of a bell ringing could differentiate that sound from other similar sounds like a doorbell or telephone ringing, that would be stimulus discrimination.

Little Albert

Ivan Pavlov's classical conditioning research did not stop with animals. Although it would be completely unethical to do today, some associates of Pavlov decided to apply his classical conditioning theory to human beings. Using a baby named Little Albert, a behaviorist named John B. Watson and his graduate student Rosalie Rayner decided to try to condition the fear response in the toddler. Researchers showed Albert a group of stimuli that included burning newspapers, masks, a monkey, a rabbit, and a white rat.

The white rat

When first introduced, Little Albert did not show fear to any of these stimuli. However, the next time the child was introduced to the white rat, Watson or Rayner would make a loud sound by hitting a steel pipe with a hammer. This scared the boy and caused him to start crying. After this was done several times, Little Albert would cry every time he saw the white rat. 

Criticisms of the experiment

The researchers found that it was not just the rat that Little Albert feared as he started to fear many different white and furry objects. Although the Little Albert Experiment was one of psychology's most famous and is prominent in many different psychology courses, it has been widely criticized for many reasons. For example, causing a child undue fear to prove a theory is considered unethical. Also, Watson and Rayner did not carefully construct or develop the objective means for the process of evaluating Little Albert's reactions.

Classical conditioning and phobias

Similar to the Little Albert experiment, phobias and anxiety disorders can be caused by classical conditioning. A phobia is an irrational fear of a situation, activity, or specific object. One example is a person who has a fear of driving an automobile because they once had a panic or anxiety attack while they were driving. Experts have found that individuals do not develop a phobia of just anything. Even though some people can develop a driving phobia, people are more likely to develop a phobia of objects such as bugs, spiders, or places like closed spaces or heights.

Classical conditioning and PTSD

Post-traumatic stress disorder (PTSD) is a serious anxiety disorder that may develop after an individual is exposed to a traumatic event such as a violent assault or attack, a natural disaster like a flood or earthquake, severe abuse, or a terrorist attack. The condition typically happens when a person develops an association between the things related to the traumatic event and the trauma itself. For example, an individual with PTSD who has been exposed to war may become afraid when they see a military uniform. Because of classical conditioning, the individual may have a panic attack when being exposed to or just thinking about the traumatic event. Knowing this, therapists and other mental health care professionals have discovered that by exposing the individual to the conditioned stimulus (military uniforms) many times without the unconditioned response (war), they can reduce their fear of the uniforms.

If you or a loved one is experiencing abuse, contact the Domestic Violence Hotline at 1-800-799-SAFE (7233). Support is available 24/7.

If you are experiencing trauma, support is available. Please see our Get Help Now page for more resources.

Classical conditioning and addiction

Classical conditioning can be beneficial in understanding how some types of addiction or drug dependency work. For instance, when someone uses a drug regularly for an extended period, the body compensates for it to counterbalance the effect of the drug. As a result, the individual will need a larger amount of the substance to get the effects they desire. With this example, the environmental response (conditional stimuli) causes your body to prepare itself for the drug (conditional response).

Getty/Vadym Pastukh
Many factors influence our behavior

Learn more about conditioning

If you want to learn more about conditioning and how it may affect your behavior, consider talking to a therapist. They can work with you to understand what may be causing your behavior and provide tools to help you change them. If you're experiencing mental health challenges or have a busy schedule, making and keeping an in-person appointment can prove challenging. You may be experiencing debilitating symptoms such as fatigue or social withdrawal that make it hard to leave the house. Online therapy may provide a solution. With internet-based counseling, you can speak to a qualified therapist from the comfort of your home. It's also more convenient since appointments are available outside normal business hours. 

Online therapy is not just convenient, though; it's also effective. Research shows that online therapy can be as effective as in-person counseling in addressing a variety of mental health conditions across various populations. You can also access various forms of therapy online, including behavioral therapy. 


Classical conditioning is just one of the many findings in psychology that may have important implications for your mental health. If you're ready to uncover the root of the problems or behaviors negatively impacting your life, consider getting matched with a BetterHelp counselor today.
Explore mental health options online
The information on this page is not intended to be a substitution for diagnosis, treatment, or informed professional advice. You should not take any action or avoid taking any action without consulting with a qualified mental health professional. For more information, please read our terms of use.
Get the support you need from one of our therapistsGet started