Stimulus generalization is one of the possible outcomes of classical and operant conditioning. In this lesson, you will learn about famous experiments involving stimulus generalization and everyday circumstances in which it occurs.
What Is Stimulus Generalization?
In classical conditioning, an association is learned between two stimuli.
In the classic experiments of Ivan Pavlov, dogs learned an association between the sound of a tone and food, in which the tone signaled that food was coming very soon. As a result, the dogs would salivate in response to only hearing the tone. In this example, the tone is considered the conditioned stimulus, and the salivation in response to hearing just the tone is considered the conditioned response.Another outcome of classical conditioning is stimulus generalization, which happens when the organism that is being conditioned learns to associate other similar stimuli with the conditioned stimulus; the organism displays the conditioned response as a consequence of being exposed to similar stimuli. If we go back to the example of Pavlov’s dogs, stimulus generalization would occur if the dog began to salivate in response to another type of sound that’s similar to the tone, such as a doorbell or wind chimes, even though it was never directly conditioned to respond to those specific sounds.
The Little Albert Case
One of the best known cases of stimulus generalization is that of Little Albert. In 1913, psychologist John Watson conducted an experiment to see if he could instill a fear of little white lab rats into an infant. This infant was Little Albert, who was naturally afraid of loud noises, but not white rats. In fact, he was initially very eager to pet the white rat. In order to develop the fear, Watson would bang a hammer on a steel bar to create a loud noise every time Little Albert tried to pet the rat. After Watson did this several times, Little Albert began to cry from only seeing the white rat.Watson ended the experiment then, since he succeeded in creating this fear; however, the conditioning process did not end for Little Albert.
He began to experience stimulus generalization, and his fear of white rats spread to other animals that were white, including rabbits. It got to the point that anything white and furry frightened him, even a white fur coat. This case is a classic example not only of stimulus generalization, but one of the early cases documenting how humans can be classically conditioned as well as animals.
Although the most well-known of Pavlov’s experiments involved the sound of the tone and food, he also conducted variations of this study. In one experiment, dogs were trained to salivate in response to being rubbed. Pavlov would rub the dog’s leg, and then it would be given food. After this happened on several occasions, the dogs would salivate just from having their legs rubbed.
Not only this, but stimulus generalization would occur in which the dogs would salivate not just from rubbing but from scratching and even just being touched. Additionally, the dogs would salivate in response to being touched on another part of their body and not just their legs.Another example of stimulus generalization in children also involves a fear response. Toddlers who were taught to fear moving cars in order to prevent them from trying to cross busy streets by themselves also experienced stimulus generalization. They began to fear not only moving cars, but moving trucks, vans, buses, and motorcycles.
Although we have been talking about classical conditioning up to this point, stimulus generalization can occur in operant conditioning as well. While classical conditioning involves learning associations between two stimuli, operant conditioning changes an organism’s voluntary behavior through reward and/or punishment. Just as operant conditioning works in a different way than classical conditioning, the way in which stimulus generalization develops within operant conditioning is different. For instance, when children are taught by a parent to tie their shoes and get rewarded for doing so successfully, they are more likely to repeat that behavior. Not only are they more likely to repeat this behavior, but they are likely to generalize this request and tie their shoes when a teacher or other adult asks them to do so in addition to the parent who originally taught them.
Let’s review. Stimulus generalization is a phenomenon that can occur in both classical and operant conditioning.
It occurs when organisms display a response to stimuli other than the one used for the original conditioning. Pavlov’s dogs experienced stimulus generalization when they began to salivate to sounds different than the tone used for conditioning a salivary response. One of the most famous cases of stimulus generalization was the case of Little Albert, in which John Watson trained an infant to fear white rats through classical conditioning, but the infant developed a generalized fear of all things white and furry.
Within operant conditioning, organisms can generalize their training by responding to a stimulus different than the original one, such as when a child learns to tie their shoes at their parent’s request but generalizes this training to include tying their shoes at the request of teachers or other adults.