Introduction to Classical Conditioning

Classical conditioning is a type of learning that had a major influence on the school of thought in psychology known as behaviorism. Discovered by Russian physiologist Ivan Pavlov, classical conditioning is a learning process that occurs through associations between an environmental stimulus and a naturally occurring stimulus.

Behaviorism is based on the assumption that learning occurs through interactions with the environment. Two other assumptions of this theory are that the environment shapes behavior and that taking internal mental states such as thoughts, feelings, and emotions into consideration is useless in explaining behavior.

It's important to note that classical conditioning involves placing a neutral signal before a naturally occurring reflex. In Pavlov's classic experiment with dogs, the neutral signal was the sound of a tone and the naturally occurring reflex was salivating in response to food. By associating the neutral stimulus with the environmental stimulus (the presentation of food), the sound of the tone alone could produce the salivation response.

In order to understand how more about how classical conditioning works, it is important to be familiar with the basic principles of the process.

The Unconditioned Stimulus

The unconditioned stimulus is one that unconditionally, naturally, and automatically triggers a response. For example, when you smell one of your favorite foods, you may immediately feel very hungry. In this example, the smell of the food is the unconditioned stimulus.

The Unconditioned Response

The unconditioned response is the unlearned response that occurs naturally in response to the unconditioned stimulus. In our example, the feeling of hunger in response to the smell of food is the unconditioned response.

The Conditioned Stimulus

The conditioned stimulus is previously neutral stimulus that, after becoming associated with the unconditioned stimulus, eventually comes to trigger a conditioned response. In our earlier example, suppose that when you smelled your favorite food, you also heard the sound of a whistle. While the whistle is unrelated to the smell of the food, if the sound of the whistle was paired multiple times with the smell, the sound would eventually trigger the conditioned response. In this case, the sound of the whistle is the conditioned stimulus.

The Conditioned Response

The conditioned response is the learned response to the previously neutral stimulus. In our example, the conditioned response would be feeling hungry when you heard the sound of the whistle.

Examples of Classical Conditioning

It can be helpful to look at a few examples of how the classical conditioning process operates both in experimental and real-worlds settings:

Classical Conditioning a Fear Response

One of the most famous examples of classical conditioning was John B. Watson's experiment in which a fear response was conditioned in a young boy known as Little Albert. The child initially showed no fear of a white rat, but after the presentation of the rat was paired repeatedly with loud, scary sounds, the child would cry when the rat was present. The child's fear also generalized to other fuzzy white objects.

Let's examine the elements of this classic experiment. Prior to the conditioning, the white rat was a neutral stimulus. The unconditioned stimulus was the loud, clanging sounds and the unconditioned response was the fear response created by the noise. By repeatedly pairing the rat with the unconditioned stimulus, the white rat (now the conditioned stimulus) came to evoke the fear response (now the conditioned response).

You can learn more about this famous study in this overview of the Little Albert experiment as well as some more information on the controversy about Little Albert.

This experiment illustrates how phobias can form through classical conditioning. In many cases, a single pairing of a neutral stimulus (a dog, for example) and a frightening experience (being bitten by the dog) can lead to a lasting phobia (being afraid of dogs).

Classically Conditioning Taste Aversions

Another example of classical conditioning can be seen in the development of conditioned taste aversions. Researchers John Garcia and Bob Koelling first noticed this phenomenon when they observed how rats that had been exposed to a nausea-causing radiation developed an aversion to flavored water after the radiation and the water were presented together. In this example, the radiation represents the unconditioned stimulus and the nausea represents the unconditioned response. After the pairing of the two, the flavored water is the conditioned stimulus, while the nausea that formed when exposed to the water alone is the conditioned response.

Later research demonstrated that such classically conditioned aversions could be produced through a single pairing of the conditioned stimulus and the unconditioned stimulus. Researchers also found that such aversions can even develop if the conditioned stimulus (the taste of the food) is presented several hours before the unconditioned stimulus (the nausea-causing stimulus). Why do such associations develop so quickly? Obviously, forming such associations can have survival benefits for the organism. If an animal eats something that makes it ill, it needs to avoid eating the same food in the future to avoid sickness or even death. This is a great example of what is known as biological preparedness. Some associations form more readily because they aid in survival.

In one famous field study, researchers injected sheep carcasses with a poison that would make coyotes sick but not kill them. The goal was help sheep ranchers reduce the number of sheep lost to coyote killings. Not only did the experiment work by lowering the number of sheep killed, it also caused some of the coyotes to develop such a strong aversion to sheep that they would actually run away at the scent or sight of a sheep.

Classical Conditioning in the Real World

In reality, people do not respond exactly like Pavlov's dogs. There are, however, numerous real-world applications for classical conditioning. For example, many dog trainers use classical conditioning techniques to help people train their pets.

These techniques are also useful in the treatment of phobias or anxiety problems. Teachers are able to apply classical conditioning in the class by creating a positive classroom environment to help students overcome anxiety or fear. Pairing an anxiety-provoking situation, such as performing in front of a group, with pleasant surroundings helps the student learn new associations. Instead of feeling anxious and tense in these situations, the child will learn to stay relaxed and calm.

More About Classical Conditioning

Classical conditioning can be used to increase the amount of a behavior, but it can also be used to decrease behavior. Learn more about some of the basic principles of classical conditioning.