The history of meridian tapping began with Dr. George Goodheart, a leading chiropractor who found he could use acupuncture points beneficially for physical conditions by just "tapping" on them (no needles were needed!)
An Australian psychiatrist, John Diamond, M.D., then took this discovery a step further. He began using verbal affirmations as the patient was stimulating the acupuncture points. This was a major step forward as it introduced a psychological tool into the process. But still the treatment method lacked a cohesive "engine" to drive it forward with real effectiveness. That engine was supplied by Dr. Roger Callahan, an American psychologist specializing in anxiety disorders.
Dr. Callahan's contribution was immense and has been well documented. Through his interest in acupuncture and his awareness of the use of the value of tapping on acupoints, he made a key discovery upon which all later meridian tapping methods are based. Callahan found that if a person is focusing on a specific fear at the time they tap, that fear can be removed, often permanently. He developed his discovery into a complete system and concluded that there was a correct tapping sequence for every emotional issue, and that this could be determined for each individual through the use of muscle testing. He called these tapping sequences "algorithms" and his treatment later became known as Thought Field Therapy, or TFT.
Dr. Callahan's work, although brilliant and groundbreaking, was however quite complex and difficult to master because different algorithms were required for each one of the numerous disorders studied.
The next step was the creation of simplified versions of Callahan's technique. These were known as "single algorithm techniques" (i.e. they did not require diagnosis or muscle testing). My own early method, Acutap, was one of the very first single algorithm methods, predating EFT by about seven years and there may have been others who devised similar adaptations of Callahan's method.
Then, in the 1990's, quite independently arrived at and without his knowledge of any former single-algorithm method, one of Roger Callahan's star pupils, Gary Craig, unveiled a major development of the meridian tapping techniques which he called Emotional Freedom Techniques (EFT). Today his single algorithm method, EFT, leads the world in the development and teaching of the meridian tapping approach to healing.