Classical conditioning is a learning process that involves pairing a previously neutral stimulus with a stimulus that naturally evokes a response. After a response has been acquired, the previously neutral stimulus will then evoke the response all on its own. Consider Ivan Pavlov’s classic experiment with dogs. By associating the presentation of food with the sound of a tone, Pavlov was able to condition the dogs to salivate to the sound. The phase in which the dogs began to salivate to the sound is the acquisition period.
How Acquisition Works
How does acquisition occur? In classical conditioning, repeated pairings of the conditioned stimulus (CS) and the unconditioned stimulus (UCS) eventually lead to acquisition. The unconditioned stimulus is one that naturally evokes the unconditioned response (UCR). After pairing the CS with the UCS repeatedly, the CS alone will come to elicit the response, which is then known as the conditioned response (CR).
Repeated Pairings Are Needed
During acquisition, the conditioned stimulus and unconditioned stimulus are repeatedly paired to create an association. Multiple pairings are required, but the number of trials needed can vary depending on what is being learned. For example, imagine that you are teaching a dog to fear the sound of a rattlesnake. This type of learning will likely occur much more quickly since the animal may already be primed to form such an association. As a result, the acquisition will happen much faster than if you are teaching the dog to play dead.
Reinforcement Can Strengthen the Response
Once the behavior has been acquired, it is still often reinforced in order to strengthen the association. For example, imagine that you are teaching a pigeon to peck a key whenever you ring a bell. Initially, you place some food on the key and sound a tone right before the pigeon pecks the key. After several trials, the pigeon begins to peck the key whenever he hears the tone, meaning he has acquired the behavior. If you stop reinforcing the behavior at this point, the bird would quickly stop engaging in the action (this is known as extinction). If you continue reinforcing the association between the bell and the food, the response will become much stronger.
Factors That Affect Acquisition
A number of factors can affect how quickly acquisition occurs. If you are trying to create a conditioned response, you may need to vary these.
Salience of the Stimulus
The salience (strength or novelty) of the conditioned stimulus can play an important role. If the CS is too subtle, the learner may not notice it enough for it to become associated with the unconditioned stimulus. Stimuli that are more noticeable usually lead to better acquisition. For example, if you are training a dog to salivate to a sound, the acquisition will be more likely if the sound is noticeable and unexpected. The sound of a bell will produce a better result than a quiet tone or a neutral sound that the animal hears regularly.
Timing of the Association
Second, timing plays a critical role. If there is too much of a delay between the presentation of the conditioned stimulus and the unconditioned stimulus, the learner might not form an association between the two.
Acquisition Examples
It can be helpful to examine a few examples of how acquisition can occur in different settings.
Acquired Fear Responses
A classic example of acquisition is the famous Little Albert experiment conducted by John B. Watson and Rosalie Rayner. In the experiment, Watson and Rayner paired the sight of a white rate with a loud clanging sound that frightened their subject, a nine-month-old boy. While the child was initially unafraid of the white rat, repeatedly pairing the sight of the rat with the clanging sound eventually led to the child acquiring a fear response. Once acquired, the child displayed fear of the rat. Today, this type of experiment would be considered unethical, because the baby was harmed by it (he experienced a fear he did not previously have).
In Real-World Settings
Fear of school can be another example of an acquired response in children. While a child might have initially enjoyed school, repeated experiences with bullying or negative interactions with a teacher might cause a child to acquire a fear response. In this case, classical conditioning could also be used to help a child acquire a more positive attitude toward school. If the child had a supportive, nurturing teacher, they may acquire a positive association that helps overcome their previous fear.
A Word From Verywell
Acquisition represents an important part of the learning process. By repeatedly pairing a neutral stimulus with something that naturally leads to a response, people are able to acquire new associations that can affect how they behave and respond in different settings. Understanding how this process works can help you can gain insight into the learning process. This can be helpful if you are trying to teach or learn a new behavior
