In this article, we will examine classical conditioning, the simple process of creating an association between the two different stimuli to create new learning.
What is Conditioning in Psychology
In the study of 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 learned association.
You can easily find classical conditioning scenarios 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 or reflexive response.
Classical conditioning was discovered by Russian physiologist Ivan Pavlov as he studied the digestive system of dogs in the early 1900s1.
Here is Pavlov’s famous dogs experiment…
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’ behavioral responses. In Pavlov’s experiment, 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, he started ringing the bell without giving them any food. Still, Pavlov’s dog would continue to salivate at the sound without the sight of food. The sound of a bell had become associated with food, and the salivation response had become a learned response. The sound of the bell became a conditioned stimulus.
Classical Conditioning Examples
Here are some examples of classical conditioning in everyday life.
1. A warm and nurturing teacher motivates students
A warm and nurturing teacher (US) makes students feel connected (UR). Students associate going to school (CS) with the teacher. Therefore, students learn to enjoy going to school (CR)2.
2. A harsh and strict teacher demotivates students
A harsh and strict teacher (US) makes students feel bad (UR). Students associate going to school (CS) with the harsh teacher and learn to feel bad about going to school (CR).
3. Fear of dogs
A child sees a dog attack a person. It’s a very frightening experience (UR). Dogs are generally neutral stimuli (US) that many people find adorable. But to this child, after this incident, he’s scared (CR) whenever he sees a dog (CS).
4. Food aversion
Food poisoning can lead to a phobia of a specific food. The first time someone eats a certain food (US) and gets sick from it, they may associate the food with feeling awful (UR). The food’s appearance, smell, or taste (CS) can evoke an intense dislike or even fear in the person (CR).
5. Anxiety over needles
Getting a flu shot (US) hurts and makes a child cry (UR). The child associates the needle (CS) with getting hurt and cries at the sight of the needle (CR).
6. Stage fright
A child is laughed at (US) when he gave a presentation in class and he felt ashamed (UR). Now every time he has to speak up in front of people (CS), he feels nervous and fearful (CR).
7. Post-traumatic Stress Disorder (PTSD)
Posttraumatic Stress Disorder (PTSD) is a mental health disorder that results from exposure to a traumatic event, such as a natural disaster or violent crime (US). Patients were victims or witnesses who experienced intense fear (UR) in the event. Location, objects, or sound are cues that could be associated with it. When such a cue is present (CS), it can trigger flashbacks and intrusive thoughts (CR) in sufferers.
8. Obsessive-compulsive disorder
OCD is characterized by intrusive and unwanted thoughts (obsessions) and the need for repetitive behaviors or mental acts (compulsions). Obsessions commonly involve germs, contamination, doubts, order, and symmetry.
The obsession often develops through classical conditioning. A person who has associated a neutral stimulus with an unconditioned stimulus is likely to feel anxious and obsessive upon further encounters with the neutral stimulus. These obsessive thoughts are the conditioned responses.
9. Praises encourage a child to feel happy about their good behavior
A parent’s praise for a child’s good behavior (US) makes them feel proud (UR). The child associates the behavior (CS) with the praises and feels proud (CR).
10. Parent turns homework into misery
If parents yell at their kids (US) for not doing homework, they feel miserable (UR). They will learn to associate homework (CS) with misery and dislike it (CR).
11. Parent turns homework into a game
Playing games with the parent (US) makes a child happy (UR). The child associates homework doing (CS) with playing games and learning to feel good about doing homework (CR).
12. Anxious about exams
Whenever a child fails an exam, they get punished (US) by their parents. The child then associates exams with bad consequences that create anxiety (UR). When the child takes an exam again (CS), they will automatically become nervous (CR).
13. Getting A’s
A child who gets all A’s on his report card is praised and rewarded by his parents (US), making him feel good(UR). Exams (CS) are associated with pride and confidence (CR) instead of anxiety and fear for him.
14. Crave for hotdogs
Every time a father brings his son to a football game, he buys him a hotdog. The child loves the feeling (UR) of spending time with his father (US). Even as an adult, he still craves hotdogs (CR) when he attends a game (CS).
15. Parents’ angry expression
When parents get angry and are about to yell, their faces and body gestures show certain angry expressions. Yelling and scolding (US) can scare small children into crying (UR). When these kids see a grownup with those expressions (CS), they spontaneously cry (CR).
Most children love playing with other kids (US). It is fun and makes them feel happy (UR). When a child sees a group of children playing with a toy in a commercial, they associate the toy (CS) with happy feelings (CR) and want to play with it, too.
17. Cellphone ring tone
People associate cellphone ring tones (US) with different feelings. If a person receives calls from friends, which makes them feel connected and happy (UR), they will learn to feel happy (CR) just hearing the tones by themselves (CS).
18. The bread-baking aroma in an open house
It has long been known that real estate agents bake bread during open houses. The aroma of baking bread is often associated with memories of childhood (US) that make people feel reminiscent (UR). Upon smelling that scent (CS) again during the open house, a person is more likely to feel at home (CR).
19. Festive music
The holiday season (US) is usually a joyful time of year filled with music, gifts, and laughter (UR). During the holiday shopping season, department stores often play holiday music (CS) to evoke a festive and generous feeling (CR).
20. Dog walking
Walking with its owner (US) is exciting for a dog (UR) who stays inside all day. So, when it sees its owner change into a sweatshirt, put on a coat, and grab the keys, it knows they’re going out. These actions alone (CS) can excite the dog (CR).
The Basics of Classical Conditioning
Let’s go over the mechanics of classical conditioning. There are multiple steps of 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, neutral stimuli (NS) do not trigger an unconditioned response. A new 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 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 the 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 responses.
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 themselves.
Properties of Classical Conditioning
Normally, for classical conditioning to occur, the conditioned stimulus needs to be presented before the unconditioned stimulus. When a 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 backward 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 learned 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 extinct behavior.
Sometimes, during the extinction process, conditioned behavior may temporarily increase instead of decrease 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 a 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 conditioning doesn’t always require repetitions to form. Sometimes, one traumatic experience is enough to create associative learning and generalization to other stimuli.
Here is another 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)7–9. Studies have shown that some patients with PTSD have lower stimulus discrimination6 leading to difficulty in extinction.
- First-order – learning is obtained by associating a neutral stimulus with an unconditioned stimulus.
- Second-order conditioning – learning by pairing a neutral stimulus with a stimulus that has previously been converted into a conditioned stimulus through first-order conditioning.
- Higher-order conditioning – learning is 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 stimulus7.
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 US8.
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 food (CS) becomes associated and you learn to avoid or dislike food with that smell and taste.
Taste aversion learning is one of the strongest types of responses that can affect human behavior. It only takes a single instance to the condition because if it signals ‘danger’, you have the last chance to refrain from ingesting the food9.
Final Thoughts on Classical Conditioning
Real-life examples of classical Conditioning often occur 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 simplistic10.
Many classical conditioning theories are based on extensive research done on lab animals. 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 conditioning in a voluntary behavior, American psychologist B.F. Skinner proposed the operant conditioning theory. Later, Skinner became the founder of behaviorism and his theory was an important pillar in behaviorism psychology.
- 1.Clark RE. The classical origins of Pavlov’s conditioning. Integr psych behav. Published online 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. Published online October 10, 2003:13087-13092. doi:10.1073/pnas.2132313100
- 4.BALSAM P. Relative Time in Trace Conditioning. Ann NY Acad Sci. Published online 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. Published online September 1984:619. doi:10.1086/208999
- 6.McFarlane AC, Lee Weber D, Clark CR. Abnormal stimulus processing in posttraumatic stress disorder. Biological Psychiatry. Published online September 1993:311-320. doi:10.1016/0006-3223(93)90088-u
- 7.Gewirtz JC. Using Pavlovian Higher-Order Conditioning Paradigms to Investigate the Neural Substrates of Emotional Learning and Memory. Learning & Memory. Published online September 1, 2000:257-266. doi:10.1101/lm.35200
- 8.Jara E, Vila J, Maldonado A. Second-order conditioning of human causal learning. Learning and Motivation. Published online August 2006:230-246. doi:10.1016/j.lmot.2005.12.001
- 9.Welzl H, D’Adamo P, Lipp HP. Conditioned taste aversion as a learning and memory paradigm. Behavioural Brain Research. Published online November 2001:205-213. doi:10.1016/s0166-4328(01)00302-3
- 10.Cooper PA. Paradigm Shifts in Designed Instruction: From Behaviorism to Cognitivism to Constructivism. Educational Technology. 1993;33(5):12-19.