Perhaps we have not got eyes in the back of our heads after all. A series of experiments that appeared to show that people innately knew when they were being stared at from behind may in fact have only picked up the ability implicitly to learn subtle patterns.
Thousands of volunteers took part in tests devised by biologist Rupert Sheldrake to detect extrasensory perception. The results appeared to demonstrate a significant effect.
However, research by John Colwell, principal lecturer in psychology at Middlesex University, which has been published in the British Journal of Psychology, suggests there may be a mundane explanation.
Dr Sheldrake's experiments involved giving out a set of strict instructions to volunteers over the internet, who then carried out the tests in their own homes and sent the scientist back their results.
They were asked to put on blindfolds and sit with their backs to other volunteers who then either stared at them or looked away according to set of random numbers that Dr Sheldrake provided. Alternatively, a coin could be tossed to determine whether the "looker" stared or not.
Dr Colwell repeated the experiments in controlled laboratory conditions using Dr Sheldrake's number sequences and a one-way mirror to separate the two volunteers.
When the subject was not told whether they were right or wrong after each test, he could find no effect. However, with feedback, an apparent ability to detect staring emerged during the course of the experiment.
Although this appeared to confirm Dr Sheldrake's hypothesis, Dr Colwell suggests this could be more to do with the mind's ability to detect subtle patterns as an analysis of the number sequences found they were not entirely random.
"There was a pattern that was alternating too much and this biased the trial in favour of detecting an effect," he said.
"Because the subjects were given feedback, they were using this information to pick up structure in the sequences."
The apparent effect disappeared when Dr Colwell used a truly random sequence.
While Dr Sheldrake's experiment does not involve giving feedback and includes the coin-tossing option, Dr Colwell suggests that in the absence of strict controls, subtle cues may be picked up by some of those test subjects using the provided sequences as an indication of whether a guess was right or wrong. This, he suggests, could skew the overall results in favour of indicating psychic phenomena.