I sometimes find myself investigating ostensibly paranormal phenomena in the role of “rent-a-sceptic”. I was recently invited to investigate apparently ghostly goings-on in a house in Leicester for ITV’s This Morning. Don, a paranormal investigator, claimed that he could communicate with the spirits involved. The Sun newspaper had posted on its web site a recording of Don apparently coaxing spirits into lowering the room temperature. As Don politely asked the spirits to lower the temperature, the digital display of his handheld thermometer appeared to show that the spirits were obliging. Armed with my knowledge of unconscious muscular activity and a tip-off from an ex-ghost-hunter, I was able to quickly solve this apparent mystery. The tip-off was that the investigator was misusing his equipment. He thought he was measuring ambient temperature but he was actually measuring the temperature of whatever the handheld device was pointing at – in this case, the wall. Heat rises, so the top of the wall was warmer than the bottom, as I was able to personally confirm. By unwittingly changing the angle of the device, thanks to unconscious muscular activity, Don was unintentionally producing the evidence of “paranormal activity” that he was so keen to find!
Professor Chris French is Head of the Anomalistic Psychology Research Unit at Goldsmiths, University of London, and editor of The Skeptic.