I don't think there's any one thing going on with hypnosis. There is no button in your brain the hypnotist pushes to cause Sudden Asleepening. I certainly don't mean to say that there's no such thing as hypnosis. But looking for an individual mechanism causing all of its features is like studying biology by searching for the source of elan vital.
Ordinary TranceHere are some ordinary kinds of experiences from everyday life that I think hypnotists have probably figured out how to replicate at will and take advantage of.
1. Suggestion: If you're cognitively taxed and experiencing a lot of dissonance, it can be an incredible relief when someone else takes over.
You just had a very long day full of important business decisions. You're having dinner at a restaurant, and you can't decide what to order off the very long menu. "Just have the turkey," says your spouse, and that's what you have. They make your decision for you, and you're happy to comply without thinking deliberatively about it any further.
It doesn't feel at all like they forced you to order the turkey. Still, they suggested you order the turkey, and you ordered it. That's complying with suggestion. You're more likely to comply with that particular suggestion when your feeling of indecision is slightly unpleasant or draining, so it's safe to say that you're in a state of heightened suggestibility when faced with a cognitively taxing dinner menu.
2. Selective attention: You never experience every element of your surroundings with equal attention. Sometimes, your attention becomes so selective that you're completely unaware of large portions of your perceptible environment.
You're in a state of flow. You're working on something you're passionate about, but it's very challenging, so you're highly focused. (Maybe you're composing music, proving a mathematical theorem, or practicing three-pointers.) Someone is standing right beside you trying to get your attention, even saying your name. Yet, when they finally touch your shoulder, you jump a bit from how surprised you are to discover them.
It's not that the sound of their voice didn't enter your ears, or that the light reflecting off of them didn't enter your eyes. Your attention was just too narrowly directed to respond to stimuli irrelevant to the object of your intense focus.
3. Catalepsy: Sometimes, you just feel too damn lazy to move.
It's your day off and you're lying in bed. The sun's pouring gently through the drapes, and you feel so warm and snugly that you don't want to move a muscle. But you know it's time to get up, so you imagine yourself moving, raising your head to find out what time it is. You tell yourself, "I'm going to move now". You even repeat silently to yourself, "Lift your head. Lift your head." But your body just won't move.
You aren't paralyzed. All your nerves are firing just fine. On some level, you feel that you could move, if you just wanted to hard enough. But you can't seem to make yourself want it enough. You can't muster up enough willpower to really try to try. For all the power your will seems to have over your legs, they might as well be made of lead.
4. Amnesia: It's normal to forget little things all the time. But occasionally a really drastic memory failure happens, and it feels as though you've jumped through time.
You're on the highway at night, and you're a little sleepy. The drive is monotonous; everything rushing by is the same, and the grey road just stretches on and on. It's about an hour till your next turn. But then, all of a sudden, there's your exit! And you think, "What? How did I just lose a whole hour?"
You obviously experienced each moment of that hour as it was happening--you know you didn't fall asleep, because if you had you would have crashed. But you just don't seem to have access to those memories for some reason. It's like you went on autopilot.
5. Reduced sensitivity to pain: This one's especially familiar to athletes.
You're in the final stretch of a marathon. You're sprinting now, giving it everything you've got, when suddenly you hit an uneven bit of ground and your ankle rolls. You know it's happened, but you keep going. There's a very mild, dull kind of nagging pain coming from your ankle, but it's easy to ignore, and you think nothing of it. After you cross the finish line, you collapse onto the grass beside the track. As you slowly catch your breath, you notice that your ankle is hurting more. Quite a lot, in fact. As you begin tearing up from the pain, you realize that you've probably sprained it severely.
There's no way you could tolerate putting weight on it at this point. Yet just a few minutes ago, you were sprinting as though nothing were wrong.
One More IngredientWhen experiences like this happen in the course of daily life, we don't usually recognize anything strange or spooky about them. If, however, we experience them when someone called a "hypnotist" is dangling a pendulum in front of us, we pay attention to them, and they no longer fuse so seamlessly with the rest of experience. Framing is everything.
Hypnosis seems to be some combination of suggestion, selective attention, catalepsy, amnesia, and reduced sensitivity to pain. These pieces of "hypnosis syndrome" happen to us frequently in all sorts of contexts. So perhaps there's one final, key ingredient to this apparently bizarre practice we call "hypnosis": the belief (or suspicion) that one is hypnotized.