When I was first a student, late night TV showed a demonstration of a hypnotic procedure for enlarging breast size. It was a live programme, and after the hypnotist had spent a while beaming out his relaxing affirmations to a group of women, most of them measured small but noticeable increases in their bust (of about an extra inch). There was no follow-up, so no evidence that this was a lasting change.
This superficially impressive demonstration puzzled me ever since: surely mere relaxation cannot add fat cells to your body in just half an hour. Was it an effect of relaxed breathing, or maybe blood flow? As I’ve just had shown to me, I should have realised that the answer was – doh! – psychological bias.
An episode in this summer’s BBC series The Bullshit Detective (you’ll notice that in a break from the norm, this post is based on TV programmes rather than research papers) took three women, gave them a ten-minute subliminal messages/hypnosis routine, and seemed to achieve a one inch growth, but the post-treatment bust measurement was made by the subjects themselves, and they noticeably slackened the tape to get that extra inch. A measurement by the host showed no expansion at all. Wanting and expecting results, the women had a motivation to exaggerate.
This is an example of the principle that when it’s difficult to make a change, it might be easier just to bias people into thinking there’s a change. Or more succinctly, sometimes minds are more flexible than reality. The important thing is to let the subjects themselves define success, so their biased perception gives the positive results.
Arguably a great deal of self-help works like this. Scientology certainly does, with its insistence on being tested against the customer’s subjective impressions rather than objective criteria. They also have the advantage that the abilities they try to boost include meaningless things like “havingness” or “beingness”, so there’s no chance that objective reality will contradict a subject’s self-satisfied perception of improvement.
A long time ago now in a skeptical newsletter (can’t find it now) a book explaining how to have out-of-body experiences was reviewed. The book told its readers to spend lots of time looking at themselves in a mirror, vividly imagining their bodies as seen from outside. The claim was that this would unleash their “astral bodies“, but clearly what was happening was that the imagery would surface again in dreams and that wishfully-thinking readers would attribute this to a genuine trip outside their bodies.
Another illusion created by this pressure to see improvement is what memory researcher Daniel Schacter calls “change bias”; remembering yourself as being worse in the past, so as to justify the effort you have put in to improving yourself: this was first identified in the context of a study skills course for students. (more about Schacter and memory bias)