In this article, we will examine classical conditioning, the simple process of creating an association between the two different “stimuli” to create a new learning.
Table of Contents
What is Conditioning in Psychology
Conditioning is the process of pairing two stimuli together so that if one stimulus can trigger a reaction, the other can do the same, too, simply by association.
You can easily find classical conditioning in everyday life.
For example, whenever you come home wearing a baseball cap, you take your child to the park to play. So, whenever your child sees you come home with a baseball cap, he is excited because he has associated your baseball cap with a trip to the park.
This learning by association is classical conditioning.
What is Classical Conditioning
Classical conditioning, also called Pavlovian conditioning, is learning through the association of a neutral stimulus with a biologically potent stimulus. The biologically potent stimulus is an involuntary response also known as reflex.
Classical conditioning was discovered by Russian physiologist Ivan Pavlov as he studied digestion in dogs in the early 1900s1.
Pavlov observed that his dogs would salivate every time he entered the room, whether or not he brought food, because the dogs had associated his entrance into the room with being fed.
Pavlov then conducted a series of experiments using different sound-making objects to condition the dogs’ responses. He sounded a bell whenever he fed his dogs. After several repetitions, the dogs began salivating as soon as they heard the sound – even before they saw the food.
Soon after, Pavlov started ringing the bell without giving them any food. Still, the dogs would continue to salivate at the sound. The sound of the bell had become associated with food, and the salivation had become a learned response.
The Basics of Classical Conditioning
Let’s go over the mechanics of classical conditioning. There are multiple stages in classical conditioning. At each stage, stimuli and responses are identified by different terminology.
The three stages of classical conditioning are before acquisition, acquisition, and after acquisition.
Phase 1: Before Acquisition
Before classical conditioning begins, the unconditioned stimulus (US) produces an unconditioned response (UR) in an individual naturally. This is a reflex reaction that doesn’t require training or practice. It is also called the primary reinforcer.
E.g.: In Pavlov’s experiment, feeding dogs food (US) naturally causes them to salivate (UR). This reaction was an unconditioned reflex.
In this stage, a neutral stimulus (NS) does not trigger an unconditioned response. This neutral stimulus could be anything, e.g. a sound, smell, taste, object, scene, etc. It doesn’t produce a response until it is paired with the unconditioned stimulus.
E.g.: Ringing the bell (NS) by itself did not elicit salivation (UR) in Pavlov’s dogs initially.
Phase 2: Acquisition
During acquisition, the neutral stimulus is paired repeatedly with the unconditioned stimulus to form an association.
Generally, it takes the a pair of stimuli multiple pairings to become associated. But sometimes, the association can be formed by a single NS-US pairing without repetition.
E.g. A dog barked (NS) and then bit (US) a child’s leg. The child was very scared (UR). When this child hears a dog bark again (CS), they tremble with fear (CR). This learning process only took one pairing to complete.
Phase 3: After acquisition
The neutral stimulus becomes a conditioned stimulus (CS). The conditioned stimulus can trigger the same response as the unconditioned stimulus can, even when it is not present. When the involuntary response is triggered by a conditioned stimulus, it is called the conditioned response (CR). The conditioned response is a learned response. The conditioned response and unconditioned response are usually the same (or similar) response.
E.g. After being paired repeatedly with food (US), the sound of the bell (NS), a previously neutral stimulus, could cause the dogs to salivate (CR) by itself.
Properties of Classical Conditioning
Normally, for classical conditioning to occur, the conditioned stimulus needs to be presented before the unconditioned stimulus. When conditioned stimulus comes before the unconditioned stimulus, the learning process is called forward conditioning2. On the other hand, backward conditioning introduces the conditioned stimulus after the unconditioned stimulus ends.
There are three types of forward classical conditioning. They affect the strength and effectiveness of learning differently.
- Delay – presents the CS, followed immediately by the US3.
- Trace – introduces a time gap between the end of the CS and the start of the US.
- Simultaneous – the two stimuli, CS and US, show up and disappear at the same time.
Associative learning is usually stronger and faster when delay conditioning is used, compared to trace conditioning. As the gap in trace conditioning is lengthened, it becomes harder to form an association4.
In most situations, delay and trace conditionings perform better than simultaneous and backward conditionings5. Research also shows that backcward conditioning doesn’t work in many situations5.
- Extinction – stopping previously conditioned response.
In Pavlov’s experiment, if he stops giving his dogs food when he rings the bell, the dogs will eventually stop salivating at the sound.
- Spontaneous recovery – the sudden return of the previously extinct behavior.
After the conditioned behavior is extinct, it may return suddenly and this phenomenon is called spontaneous recovery.
- Extinction burst – a temporary increase in frequency, duration, or magnitude of the extincted behavior.
Sometimes, during the extinction process, conditioned behavior may temporarily increase instead of decreasing because the individual is trying to bring back the unconditioned stimulus.
Stimulus & Fear Conditioning
- Stimulus generalization – when a new stimulus that is similar to the conditioned stimulus can evoke the same conditioned response without the need to condition.
- Stimulus discrimination – the opposite of generalization. It’s the ability to discern between two similar stimuli.
The infamous Little Alert experiment demonstrates the concept of stimulus generalization well. In this controversial study, researcher John B. Watson conditioned baby Albert to be afraid of a white rat (CS) by pairing it with a frightening clanging sound (US). After repeatedly making the loud sound whenever the child touched the animal, baby Albert became scared simply by seeing the animal (CR).
Watson found that the baby’s fear of the white rat wasn’t limited to only white rats. The baby became scared of other small animals, too, such as white rabbits or dogs. The poor child also became scared of white soft objects such as white cotton balls. So the fear of one stimulus was generalized to the fear of other stimuli that shared similar properties.
Fear condition doesn’t always require repetitions to form. Sometimes, one traumatic experience is enough to create associative learning and generalization to other stimuli.
Here is an example of classical conditioning. When driving through an intersection, you were hit by a car that ran a red light and got severely injured. You are now fear-conditioned to feel nervous whenever you drive towards an intersection, any intersection, not just the one you got hit in. The anxiety can be so high that you don’t want to drive ever again. That is how stimulus generalization creates anxiety disorders.
Classical conditioning created by an extreme aversive event like this can be very powerful and result in phobia, panic disorder or post-traumatic stress disorder (PTSD)6–8. Studies have shown that some patients of PTSD have lower stimulus discrimination9 leading to difficulty in extinction.
- First-order – learning is obtained by associating a neutral stimulus with an unconditioned stimulus.
- Second-order – learning by pairing a neutral stimulus with a stimulus that has previously been converted into a conditioned stimulus through first-order conditioning.
- Higher-order – learning acquired by pairing a neutral stimulus with another stimulus previously conditioned. Higher-order conditioning is intrinsically weaker than its first-order counterpart. But the strength can be increased by using a robust unconditioned stimulus10.
There are three phases in second-order conditioning. In the first training phase, a CS1 conditioned stimulus is presented before the unconditioned stimulus (US) to establish a conditional relationship. In the second phase, a second conditioned stimulus (CS2) is followed by CS1, so that finally, CS2 evokes the same conditioned response (CR) even though CS2 was never directly paired with the US11.
Second-order and higher-order classical conditioning are employed frequently in consumer product marketing. For example, a sports personality is associated with an exciting game. When a product company uses a sports personality to promote its product, the goal is to foster associations between the product and the positive feelings from attending an exciting sports game5.
How Taste Aversion is Acquired
To survive in a world with varying food types and sources, humans and animals are wired to learn which food is safe and which is not safe to eat.
When you eat a sickness-inducing food (US) that causes nausea (UR), the combination of the smell and taste of that food (CS) becomes associated and you learn to avoid or dislike food with that smell and taste.
Taste aversion learning is an especially strong type of conditioning that can affect human behavior because if it signals ‘danger’, you have the last chance to refrain from ingesting the food12.
Classical Conditioning in the Classroom
Classical conditionings happen a lot in school and can often affect a child’s academic performance.
If a teacher is warm and nurturing (US), students feel connected and attached (UR). Students then associate going to school (CS) with connected feelings (CR) and learn to like going to school13. If students are friendly and helpful to one another (US), students find it fun (UR) to go to school. Students associate going to school (CS) with fun (CR) and look forward to attending every day14.
On the other hand, if a teacher is harsh and strict (US), students don’t like going to school (UR). They associate going to school (CS) with bad feelings (CR). They learn to dislike school and studying. If students are bullied in school (US), they are scared and hurt (UR). Students then associate going to school (CS) with scare and hurt (CR), and they are more likely to drop out15.
Using Classical Conditioning in Parenting
Classical conditioning occurs frequently throughout childhood. Both positive and negative child behaviors can be elicited by the parents using classical conditioning, either wittingly or unwittingly.
For instance, a parent can turn “doing homework” into a game. Playing games (US) are fun (UR). After repeatedly paired together, doing homework (CS) and having fun (CR) create a positive association in the child.
Another classical conditioning example is getting flu shots. A child’s first experience with a needle is almost always negative. Having their delicate skin pierced (US) for the first time was painful (UR) and memorable. Most children associate the needle (CS) with pain (CR) and cry at the sight of it.
Parents using praises (US) to help children feel good (UR) about their good behavior (CS) is another example. Praised children are proud of themselves (CR) and feel encouraged to engage in more good behavior.
Final Thoughts on Classical Conditioning
Classical Conditioning often occurs unconsciously. Even though when used appropriately, it can be beneficial, there is a good reason why behaviorism has fallen out of favor – it is too simplistic16.
Many classical conditioning theories are based on lab animal studies. But humans are not lab animals. Learning by association is a lot more complicated when applied to humans because our behavior is often motivated by more than just the environment. For instance, over-praising may not be a good thing. Whenever possible, parents should utilize intrinsic motivation to entice learning in children rather than extrinsic motivation.
To account for more than just involuntary classical conditioning, psychologist B.F. Skinner proposed the operant conditioning theory that later became another pillar in behaviorism psychology.
- 1.Clark RE. The classical origins of Pavlov’s conditioning. Integr psych behav. October 2004:279-294. doi:10.1007/bf02734167
- 2.Anderson M. Classical Conditioning. SUNY Cortland, The State University of New York. https://web.cortland.edu/andersmd/ccond/clascon.html.
- 3.Han CJ, O’Tuathaigh CM, van Trigt L, et al. Trace but not delay fear conditioning requires attention and the anterior cingulate cortex. Proceedings of the National Academy of Sciences. October 2003:13087-13092. doi:10.1073/pnas.2132313100
- 4.BALSAM P. Relative Time in Trace Conditioning. Ann NY Acad Sci. May 1984:211-227. doi:10.1111/j.1749-6632.1984.tb23432.x
- 5.McSweeney FK, Bierley C. Recent Developments in Classical Conditioning. J CONSUM RES. September 1984:619. doi:10.1086/208999
- 6.Maren S. Neurobiology of Pavlovian Fear Conditioning. Annu Rev Neurosci. March 2001:897-931. doi:10.1146/annurev.neuro.24.1.897
- 7.Peri T, Ben-Shakhar G, Orr SP, Shalev AY. Psychophysiologic assessment of aversive conditioning in posttraumatic stress disorder. Biological Psychiatry. March 2000:512-519. doi:10.1016/s0006-3223(99)00144-4
- 8.Careaga MBL, Girardi CEN, Suchecki D. Understanding posttraumatic stress disorder through fear conditioning, extinction and reconsolidation. Neuroscience & Biobehavioral Reviews. December 2016:48-57. doi:10.1016/j.neubiorev.2016.08.023
- 9.McFarlane AC, Lee Weber D, Clark CR. Abnormal stimulus processing in posttraumatic stress disorder. Biological Psychiatry. September 1993:311-320. doi:10.1016/0006-3223(93)90088-u
- 10.Gewirtz JC. Using Pavlovian Higher-Order Conditioning Paradigms to Investigate the Neural Substrates of Emotional Learning and Memory. Learning & Memory. September 2000:257-266. doi:10.1101/lm.35200
- 11.Jara E, Vila J, Maldonado A. Second-order conditioning of human causal learning. Learning and Motivation. August 2006:230-246. doi:10.1016/j.lmot.2005.12.001
- 12.Welzl H, D’Adamo P, Lipp H-P. Conditioned taste aversion as a learning and memory paradigm. Behavioural Brain Research. November 2001:205-213. doi:10.1016/s0166-4328(01)00302-3
- 13.Hughes JN. Longitudinal Effects of Teacher and Student Perceptions of Teacher-Student Relationship Qualities on Academic Adjustment. The Elementary School Journal. September 2011:38-60. doi:10.1086/660686
- 14.Wentzel KR, Caldwell K. Friendships, Peer Acceptance, and Group Membership: Realtions to Academic Achievement in Middle School. Child Development. December 1997:1198-1209. doi:10.1111/j.1467-8624.1997.tb01994.x
- 15.Cornell D, Gregory A, Huang F, Fan X. Perceived prevalence of teasing and bullying predicts high school dropout rates. Journal of Educational Psychology. 2013:138-149. doi:10.1037/a0030416
- 16.Cooper PA. Paradigm Shifts in Designed Instruction: From Behaviorism to Cognitivism to Constructivism. Educational Technology. 1993;33(5):12-19.