Human conditioning: Little Albert

The Little Albert experiment was an experiment showing empirical evidence of classical conditioning in humans. This study was also an example of stimulus generalization. It was conducted in 1920 by John B. Watson along with his assistant Rosalie Rayner. John B. Watson, after observing children in the field, was interested in finding support for his notion that the reaction of children, whenever they heard loud noises, was prompted by fear. Furthermore, he reasoned that this fear was innate or due to an unconditioned response.He felt that following the principles of classical conditioning, he could condition a child to fear another distinctive stimulus which normally would not be feared by a child.

The experiment:
Watson and his colleague did not begin to condition Little Albert until approximately two months later, when he was just over 11 months old. The experiment began by placing Albert on a mattress on a table in the middle of a room. A white laboratory rat was placed near Albert and he was allowed to play with it. At this point, the child showed no fear of the rat. He began to reach out to the rat as it roamed around him. In later trials, Watson and Rayner made a loud sound behind Albert's back by striking a suspended steel bar with a hammer when the baby touched the rat. Not surprisingly in these occasions, Little Albert cried and showed fear as he heard the noise. After several such pairings of the two stimuli, Albert was again presented with only the rat. Now, however, he became very distressed as the rat appeared in the room. He cried, turned away from the rat, and tried to move away. Apparently, the baby boy had associated the white rat (original neutral stimulus, now conditioned stimulus) with the loud noise (unconditioned stimulus) and was producing the fearful or emotional response of crying (originally the unconditioned response to the noise, now the conditioned response to the rat).

This experiment led to the following progression of results:
1. Introduction of a loud sound (unconditioned stimulus) resulted in fear (unconditioned response), a natural response.

2. Introduction of a rat (neutral stimulus) paired with the loud sound (unconditioned stimulus) resulted in fear (unconditioned response).

3. Successive introductions of a rat (conditioned stimulus) resulted in fear (conditioned response). Here, learning is demonstrated.