Dr. John G. Kappas, Ph.D. evolved this "Theory of Mind" over the course of many years of observation and practice. In it, he attempts to explain how our minds work and why hypnosis is possible.
At birth, our minds are like sponges. We soak in everything that happens to us and store it away as experiences. We've got a bunch of needs programmed in as well as some fears. As we grow, we have experiences, both good and bad and these are stored away. These experiences become who we are. Interestingly enough, we prefer things we know, to things that are unknown. As a result, if we have an experience and we store that away in our memories, even if the experience is something you might consider negative, we will choose that path again over a path we don't know.
Somewhere around the age of eight or nine, earlier in some, later in others, we start to develop into who we are going to be later in life. The part we think of as "us" begins to form and we begin to be more and more critical of the things that happen to us, refusing to let them enter into our long-term storage unless they line up with the things that are already there and don't conflict with them.
Dr. Kappas estimated that this conscious part of the mind that we develop is about 12% of our mind. The other 88%, consists of those stored experiences, as well as the "primitive" area that came preprogrammed into us.
So there you are, going through life with about 12% of your mind making up the part you think of as "you" and 88% under the surface, like an iceberg, impacting how you react to things at every turn. Some things that you experience make it through your filters and become logged away as experiences in the 88%. Other things are rejected and never become embedded in who you are.
Now imagine you want to change something about yourself. Maybe your doctor said it was time to lose some weight. In the 12%, you know that is a good idea. You will be healthier, feel better, look better and maybe even live longer. Yet at every step along the way, things seem to go wrong. You just can't seem to make it to the gym and you keep finding yourself with a cookie in your hand, cheating on your diet, even though you know better.
It's not enough for the 12% to want to change. The 88% will win every time. Remember how the subconscious, the 88% likes "knowns", even if they are negative? To it, the gym is scary. It's an unknown. It would rather stick with the status quo than take a risk with that unknown. As for the diet, those cookies have definite positive associations in the subconscious. It's going to want more...
Under these conditions, the subconscious is slow to change. If you can keep a sustained effort going, it is possible, but that is sheer willpower at work. Daily affirmations might help, as will creating new habits and new, positive associations with them. But, most people will fail.
But what if you could get past the critical "firewall" of your mind and insert a few positive associations in place of the negatives and unknowns you have about losing weight and going to the gym? In the same way that the 12% will always lose in a "tug-of-war" with the 88%, it can't lose when both parts are united.
In a nutshell, THAT is hypnosis.
If you'd like to know more, here's John Melton C.Ht., one of my instructors while I was in school, giving a thirty minute lecture on the Theory of Mind as developed by Dr. John G. Kappas, Ph.D., founder of the college of hypnotherapy I graduated from.