Ask a room of hypnosis researchers what hypnosis is and you will start an argument that has been running since the 1950s. On one side are those who say it is a distinct state of consciousness. On the other are those who say it is ordinary psychology in an unusual social situation. It is known as the state versus non-state debate.
The state view
State theorists hold that a hypnotic induction produces an altered state of consciousness, and that this state is what makes the unusual responses possible.
The most influential version came from Ernest Hilgard at Stanford. His neodissociation theory proposed that the mind has several control systems, normally coordinated by an “executive.” In hypnosis, the systems partly separate. One part carries out a suggestion while another, behind an amnesia-like barrier, is unaware of doing so. That is why a hypnotic response feels involuntary.
The hidden observer
Hilgard’s best-known evidence came from experiments in the 1970s. A hypnotized person placed a hand in ice water, having been given a suggestion that they would feel no pain. They reported little or none. But when told that a “hidden part” of them knew what was really going on and could report through writing or a key press, that part reported considerable pain.
Hilgard called it the hidden observer, and took it as evidence that pain was being registered and then kept out of awareness.
The non-state view
Non-state theorists, also called sociocognitive theorists, say no special state is needed. The psychologist Nicholas Spanos, who carried out some 250 studies, argued that hypnotized people are not passive. They are actively doing what the situation calls for, guided by their expectations and beliefs about hypnosis, and experiencing the result as involuntary.
Their main arguments:
- Suggestions work without an induction. People respond to the same suggestions nearly as well when simply asked to imagine, with no hypnosis mentioned.
- Motivated people match hypnotized people. Highly motivated volunteers, told to try hard, can reproduce most hypnotic effects.
- The hidden observer follows instructions. Spanos showed that hidden-observer reports changed depending on what people had been told to expect. Tell them the hidden part feels more pain, and it does. Tell them it feels less, and it does.
Other researchers in this camp include Theodore Barber, who stressed imagination and attitude, and Irving Kirsch, who stressed expectation.
What brain imaging adds
Imaging studies have complicated the picture for both sides.
- In highly hypnotizable people, hypnosis is associated with changes in activity and connectivity in networks involved in attention and self-monitoring.
- Suggested experiences are accompanied by matching brain activity. Suggested pain relief changes activity in pain-related regions. Suggested colour changes activity in colour-processing regions.
State theorists see this as proof of an altered state. Non-state theorists reply that any change in experience shows up in the brain, and that this does not prove a unique state caused it.
Where things stand
Most researchers today hold a middle position:
- Hypnotic responses are real, not faked.
- Expectation, motivation and context matter a great deal.
- Individual differences in hypnotizability are large and stable.
- For highly hypnotizable people, something distinctive does seem to be happening in the brain.
- Whether to call it a “state” is partly a question of definition.
The debate has cooled into a recognition that both sides were describing parts of the truth.
Why it matters to you
- You do not have to feel “under.” If no special state is required, there is no trance to wait for.
- Your attitude counts. Expecting it to help, and joining in, improves results.
- You are an active participant. Hypnosis is something you do, not something done to you.
- It is still real. Being driven partly by expectation does not make the pain relief any less genuine.
The bottom line
After seventy years of argument, the fairest summary is that hypnosis involves genuine changes in experience, produced by a mix of personal ability, expectation and focused attention. Whether you call that a state matters less than the fact that it works.
Next in the series: Forensic Hypnosis: Why Courts Stopped Trusting Hypnotized Witnesses
This article is for general information and is not medical advice.