Little Albert experiment

The Little Albert experiment was a controlled experiment showing empirical evidence of classical conditioning in humans and operant conditioning in humans. The study also provides an example of stimulus generalization. It was carried out by John B. Watson and his graduate student, Rosalie Rayner, at Johns Hopkins University. The results were first published in the February 1920 issue of the Journal of Experimental Psychology.

After observing children in the field, Watson hypothesized that the fearful response of children to loud noises is an innate unconditioned response. He wanted to test the notion that by following the principles of the procedure now known as "classical conditioning", he could use this unconditioned response to condition a child to fear a distinctive stimulus that normally would not be feared by a child (in this case, furry objects).

The aim of Watson and Rayner was to condition a phobia in an emotionally stable child. For this study they chose a nine-month old infant from a hospital referred to as "Albert" for the experiment. Watson followed the procedures which Pavlov had used in his experiments with dogs.

Before the experiment, Albert was given a battery of baseline emotional tests: the infant was exposed, briefly and for the first time, to a white rat, a rabbit, a dog, a monkey, masks (with and without hair), cotton, wool, burning newspapers, and other stimuli. Albert showed no fear of any of these items during the baseline tests.

For the experiment proper, Albert was put 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, Watson and Rayner made a loud sound behind Albert's back by striking a suspended steel bar with a hammer each time the baby touched the rat. Albert responded to the noise by crying and showing fear. After several such pairings of the two stimuli, Albert was presented with only the rat. Upon seeing the rat, Albert got very distressed, crying and crawling away. Apparently, the infant associated the white rat with the noise. The rat, originally a neutral stimulus, had become a conditioned stimulus, and it was eliciting an emotional response (conditioned response) similar to the distress (unconditioned response) originally given to the noise (unconditioned stimulus).

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