When self-proclaimed psychics appear to bend metal using their mind alone, there are many possible explanations for what's really going on, from object substitution to the use of concealed force. But one of the hardest aspects to explain away is eye witness accounts that the metal object continues to bend after the performer puts it down (so-called 'after effects'). A new study by Richard Wiseman and Emma Greening at the University of Hertfordshire provides compelling evidence that it could all be down to verbal suggestion.
Forty-six undergrads watched a two-minute video of a performer bending a key, apparently using mind power, and then placing it on a table. For half the students only, the performer could be heard uttering one sentence suggesting the key was continuing to bend once on the table (it wasn't). Afterwards, 40 per cent of the students who were played the performer's suggestive comment agreed with the statement that the key had continued to bend. In contrast, only 5 per cent of students who weren't played his comment agreed it had continued bending.
The experiment was repeated with 100 students and an open-ended questionnaire for them to describe what happened. Those students played the performer's suggestive comment were more likely to write afterwards that the key had continued bending. But they seemed unaware of the performer's suggestion - of those students who wrote that the key kept bending, few mentioned his comment.
The results show that it is "possible to create... psychokinetic metal bending 'after effects' via verbal suggestion alone", the authors said.
Wiseman, R. & Greening, E. (2005). 'It's still bending': verbal suggestion and alleged psychokinetic ability. British Journal of Psychology, 96, 115-129.