What is Energy Psychology such as EFT tapping and how valid is it?

EFT tapping is effective and makes use of the property of memories that they are malleable when recalled with emotion. Emotional memories - the ones of most importance to us - can be 'edited' when they are in active recall.

In psychotherapy we help our client discover contradictory memories and experiences that will induce the emotional brain to revise the memory. We present the two memories in an active state - with emotion - alternately several times. Change in the memory occurs.

Eye movements have been used in another form of psychotherapy to accomplish the same thing.

EFT is a form of energy psychology and uses tapping on different meridian points to  discharge the memory of its emotional charge. The theory is controversial, or unconventional, because it assumes the presence of the body's energy meridians. Western science has not accepted their presence although they are used in acupuncture.

The 'scientific validity' of EFT depends on a science that much of western medicine does not accept. However, true science depends on observation. If there are many observations (testimonies) of success then the method is valid. On that basis I would say it is valid. But only if you can accept 'there are more things true than are dreamt of in our philosophies.'