What Is Conditioned Stimulus, And How Does It Play A Role In Psychology?

Medically reviewed by Laura Angers Maddox, NCC, LPC
Updated April 24, 2024by BetterHelp Editorial Team

Conditioned stimulus refers to reinforcement resulting in individuals altering their behavioral processes so that a specific response becomes more frequent or predictable. This form of learning usually involves one of two parameters, including a given stimulus or signal to create a response and a response that occurs more regularly in a well-specified, stable environment. A conditioned stimulus is one of the critical components of the conditioning theory.

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Conditioned stimulus definition

A conditioned stimulus is a learned substitute stimulus that causes the same response as an unconditioned stimulus. A conditioned stimulus is a neutral stimulus that garners a response over time and training by repeatedly pairing it with another naturally occurring stimulus.

The difference: Conditioned stimulus vs. unconditioned stimulus

Understanding the meaning of the word "stimulus" can be essential for understanding the difference between what makes a conditioned stimulus work and what makes an unconditioned stimulus work. A stimulus is any external or internal event, situation, or agent that elicits a response. It is commonly understood as the cause of a human or animal's behavioral response.

The main difference between a conditioned and unconditioned stimulus is that a conditioned stimulus is a product of learned behavior.

An unconditioned stimulus is any stimulus that naturally and automatically causes a specific response in humans or organisms. A stimulus response may also be the result of operant conditioning, also known as instrumental conditioning, in which rewards and/or punishments are used to modify behaviors.

The study of applied behavior analysis (ABA) considers how an object or event causes a conditioned response measurable in the nervous system and sensory organs. In ABA the term “discriminative stimulus” is used to define any signal that a person receives which elicits a response.

Pavlov and conditioned stimulus

One of the most widely known examples of a conditioned stimulus is the research conducted by Russian physiologist Ivan Pavlov. His research in classical conditioning (a form of associative learning) was notable for demonstrating how to create associations between the occurrence of one event that elicits a response and the anticipation of another.

Pavlov's dog experiments

Ivan Pavlov unintentionally discovered pavlovian conditioning while conducting research on animals' gastric systems. He found that dogs' physical reactions to food, specifically saliva production, occurred while hearing or smelling the meal before the food arrived. This standard, unconditioned stimulus is expected since saliva plays a vital role in the digestive response of animals (and humans). During Pavlov’s experiment, he also noticed that the dogs could be conditioned to associate a previously neutral stimulus with feeding time unconsciously.

In his experiment, Pavlov placed dogs in harnesses in an isolated environment. Starting by presenting food in a bowl, he would then use a device to measure the rate of the dog’s saliva secretions. During the experiment, the dogs' salivating would begin once the researcher opened the door to feed them. The door opening was a neutral event, but the dogs began to associate the opening door with being fed. Thus, a conditioned stimulus was created when the door opened, and dogs began to salivate.

Pavlov continued to test his theory using different conditioned stimuli, including the sound of a bell or metronome, and even electrical shocks. In his bell tests, Pavlov would ring a bell shortly before blowing an air puff of food powder into a dog's mouth, using the same controlled environment as his previous experiments. The bell ringing would then be associated with food much in the same way the door had been before. As such, hearing the sound of the bell (a conditioned stimulus) caused the dogs to salivate.


How conditioned stimulus works

Often, time is required for neutral stimuli to become conditioned stimuli. This period is called the acquisition phase. During this time, humans or animals learn to connect the neutral stimulus with the unconditioned response. These repeated connections transform the neutral stimulus into a conditioned stimulus.

Conditioned stimuli can fade or become "extinct"

If a conditioned stimulus no longer follows the unconditioned stimulus, the conditioned response may fade in a process known as extinction. Once Pavlov's dogs associated a specific tone with food, he began making the sound but not providing food. Over time, when hearing the tone, the dogs produced less saliva in a process known as "experimental extinction" or unlearning the association.

Once experimental extinction occurs, Pavlov's research suggests it is not entirely wiped from the mind. The dogs would again reinstate their conditioned responses by reintroducing the original conditioning of tones and then food. This process is known as spontaneous recovery.

Conditioned stimulus psychology definition and stimulus generalization

Another finding of Pavlov's experiments was the dogs' ability to generalize the conditioned stimuli to other similar stimuli. For example, when a tone was used as a conditioned stimulus, Pavlov would differ the tones and still get the same conditioned or automatic response. This response was often more pronounced when the tones were closer to the original stimulus. 

In addition to stimulus generalization, it's also possible to discriminate between various stimuli. Stimulus discrimination involves separating similar stimuli to may otherwise elicit similar responses. So for example, if you are always the one to feed your dog, they may associate you with feeding time and begin to salivate or bark excitedly. But if your partner suddenly starts feeding your dogs, they may not have the same initial reaction (until they become conditioned.) 

That being said, over time a conditioned stimulus can condition another stimulus. This process is known as second-order or higher-order conditioning. For example, if a dog hears a can opener before he is fed, the sound would be the original conditioned stimulus. If the owner must take the can opener out of a cabinet before using it, the dog may eventually associate the owner going to a cabinet with being fed. Second-order conditioning is often the highest level of conditioning that can be achieved. Trying to use more than two conditioning levels could prove difficult or ineffective.

Conditioned stimulus isn't just for the dogs

Dogs aren't the only ones who learn from conditioning. Conditioned stimuli are consistently present in many individuals' everyday lives. By understanding the conditioned stimulus definition, you may better understand how stimuli shape your thought patterns and behaviors. 

John B. Watson used Pavlov's findings in the early 20th century to reproduce classical conditioning in a young child. This unethical experiment took one patient, an emotionally stable nine-month-old child, and subjected him to classical conditioning to create a phobia. The experiment specifically intended for him to experience fear when encountering white fuzzy animals. During the "Little Albert Experiment," Watson introduced the child to furry animals, including rabbits, dogs, and white rats.

When "Albert" was around the rat, Watson made loud, unpleasant noises that distressed Albert. Soon, the conditioned stimulus of the loud noise elicited fear in Albert, specifically toward the rat. Albert's fear generalized to other furry animals and Watson in a white furry mask without further conditioning. This experiment had shortfalls and crossed ethical boundaries not established at the time. However, it can serve as a reminder of how conditioning can shape one's thoughts and behaviors.

Examples of real-life conditioned stimulus 

However, classical conditioning using a controlled stimulus isn't only used in the laboratory. Below are a few examples of everyday conditioned stimuli and how they can affect one's life. 

TV example 

Every evening Jack enjoys his favorite television show with a cup of tea. This will eventually trigger an association between that specific show and having tea. So as time goes on, every time the show starts (conditioned stimulus), Jack gets a craving for a cup of tea.

Car example 

When Lisa, a parent, comes home from work, they pull their car into the garage. Lisa's children then hear the garage door opening from inside the house. Soon, the children associate the sound of the garage door (conditioned stimulus) with Lisa coming home. 

Yoga example 

A parent of a young child tries to practice yoga while their child is taking an afternoon nap. As part of the nap routine, the parent reads a couple of books to their child. They may start thinking about their yoga routine as they read the books (conditioned stimulus).

Potato salad example 

One day at a family picnic, Sam has a plate of potato salad that had been sitting out for a day. That night, he feels unwell and becomes ill. The potato salad was initially a neutral stimulus, but the illness turned it into a conditioned stimulus. Now, every time Sam sees or smells potato salad, the aversive conditioning of his experience causes him to think of the time he got sick eating it. This example could also be considered a psychological food aversion.

Car accident example 

As Lily backed out of a parking space (neutral stimulus), another driver ran into her car, causing an accident. After the experience, when Lily backs out of a parking spot, she feels a tinge of hypervigilance and anxiety. The fear conditioning that resulted from the car accident turned backing out of a parking space into a conditioned stimulus.

How classical conditioning can be used in therapy and counseling

Human brains are optimized to search, perceive and respond to the world with automatic associations and pattern matching. This process allows individuals to respond in ways they learn are effective and normal. Inherited and learned thought patterns allow individuals to respond to stimuli quickly and subconsciously.

However, the brain's pursuit of efficiency can create depressive, addictive, or traumatic thought patterns impacting mental health and well-being. These thought patterns can be repaired or replaced with healthier ones through therapy.

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

Two ways conditioning is taught in therapy

Below are two ways a therapist might help clients use conditioning to their advantage during therapy. 

Changing self-talk 

Words can be associated with various emotions and behaviors. The words you think to yourself can have such a great impact on you, especially when they are positive. On the other hand, self-defeating thoughts and negative self-talk can cause mental health challenges and distress. A licensed therapist can help you restructure thought patterns and self-talk in a productive way for your mental health and wellness. This process is often referred to as cognitive restructuring.

Changing how you think about places 

Due to past experiences, places can have strong associations. A painful visit to the dentist as a child could unconsciously make you feel anxious before every dentist appointment. Therapists can offer relief to anxiety by asking individuals to imagine the dentist as a positive experience necessary for health or desensitize the fear through safe and ethical conditioning like exposure therapy.

Getty/Vadym Pastukh
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Counseling options 

If you are considering therapeutic care but feel traditional settings are too expensive or inconvenient, an online therapist may benefit you. A study published in the journal Clinical Psychology Review noted that online mindfulness-based interventions (MBIs) could significantly contribute to enhanced mental health, especially regarding daily stressors that impact the quality of living. Studies in the paper reported that up to 92% of individuals could adhere to the training and practices recommended by online MBIs.

Advancements in telehealth technologies can bring strategies such as online MBIs to you. If you are considering online counseling, consider signing up for a platform like BetterHelp, which offers qualified and licensed therapists. In the convenience of your home, an experienced therapist can help with conditioning or many other proven strategies for improving mental health. 

You can evaluate each therapist based on your needs and select someone with experience and training in your area of concern. Additionally, online therapy sessions can sometimes be conducted around your schedule and outside of standard business hours. 


Conditioned stimulus refers to the type of reinforcement that results in people altering their behavioral processes such that a response becomes more frequent or predictable. Understanding conditioned stimulus can help you understand how specific therapeutic modalities work and how humans form habits. If you're interested in learning more or speaking to a professional, consider contacting a therapist online or in your area for guidance.
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