The Little Peter Experiment

In 1924 the psychologist Mary Cover Jones published a study, often called the Little Peter experiment, in which she worked with a three-year-old boy who had an existing fear of white furry objects, including a white rabbit, to test methods of removing a learned fear through gradual behavioral treatment. Jones's most effective method, which she called direct conditioning, involved bringing the rabbit progressively closer to Peter over repeated sessions while he ate a favored food, pairing the previously frightening stimulus with a pleasant one so that the pleasant association could gradually override the fear response, and she supplemented this with social learning by allowing Peter to watch other children handle the rabbit calmly. Across the sessions Peter's fear diminished steadily, from an initial refusal to be in the same room as the rabbit to eventually holding and playing with it without distress, and his reduced fear generalized to other furry objects such as cotton wool and a fur coat that had also previously frightened him. Conducted under Jones's mentor John B. Watson not long after Watson's own Little Albert experiment had shown that a fear response could be conditioned into a child, the Little Peter study is generally regarded as the earliest experimental demonstration in the psychological literature of counterconditioning, the deliberate unlearning of a conditioned fear, and it anticipated methods later formalized as systematic desensitization in behavior therapy.