NLP was discovered by watching theraputic experts doing what they did and modelling their behviour so that it could be taught to others to allow them to achieve the same results.
Wikipedia defines NLP as:
Neuro-linguistic programming (NLP) is an approach to communication, personal development, and psychotherapy created in the 1970s. The title refers to a stated connection between the neurological processes ("neuro"), language ("linguistic"), and behavioral patterns that have been learned through experience ("programming") and can be organized to achieve specific goals in life.
The founders of NLP, Richard Bandler and John Grinder, say that NLP is capable of addressing problems such as phobias, depression, habit disorder, psychosomatic illnesses, and learning disorders. Their stated aim was in "finding ways to help people have better, fuller and richer lives." Bandler and Grinder claimed that if the effective patterns of behaviour of exceptional people could be modeled then these patterns could be acquired by others. NLP has been adopted by private therapists, including hypnotherapists, and in management workshops and seminars touted to business and government.