How did psychologists learn to treat fear without digging into the past?

Behaviour therapy treats a problem as something learned, so it can be unlearned. It uses techniques derived from behaviourism, looking at specific learned behaviours and how the environment influences them, and it is based on Pavlov's classical conditioning and Skinner's operant conditioning. Its followers tend to look for outcomes that can be measured objectively.

The story starts with fear. In John B. Watson's "Little Albert" experiment, an infant was conditioned to fear a white rat by pairing it with a loud noise. After hearing Watson lecture in 1919, a young psychologist named Mary Cover Jones wondered about the reverse: could conditioning remove fears? Her subject was Peter, a three-year-old afraid of a white rabbit. She paired the rabbit with a pleasant thing, his favourite food. The rabbit began 12 feet away and was brought closer, bit by bit, while he ate, until his fear subsided and he could touch it without crying. Published in 1924 and now considered revolutionary, the study was largely dismissed at the time and was not even written up as her dissertation. Joseph Wolpe later dubbed her "the mother of behavior therapy".

Joseph Wolpe, a South African psychiatrist, built on it. As an army medical officer he treated soldiers with "war neurosis" using the mainstream psychoanalytic method of the day, which did not work, and he was forced to question the Freudian approach he had followed. In the 1950s he developed systematic desensitization: build a hierarchy of fears, learn relaxation, then face each situation in turn from the least frightening, on the principle that anxiety and relaxation cannot coexist.

Instead of uncovering root causes in the past, it proposed treatment that was measurable, tangible and based on evidence. Exposure therapy, a technique within behaviour therapy, is backed by numerous studies for conditions such as OCD, PTSD and specific phobias.