All Placebos are not created equal (2021)

A pair of Perkins Tractors Have you ever heard of a Perkins Tractor? If you lived in London in the 18th Century, you could buy a pair of Perkins Tractors (shown above) for the steep price of five guineas, and wave them over an aching part of your body for about twenty minutes as a way of relieving your pain. They worked, sort of. People who bought and used Perkins Tractors really did report feeling that their pain had gone away, even though there was no physiological reason they should work. John Haygarth, a British doctor, was intrigued. He organised a trial at a British hospital with several patients who were treated with fake Perkins Tractors - instead of being made of the expensive metal alloys, they were made with cheap wood. They worked just as well as the Perkins Tractors that were selling in London street stalls for five guineas, and thus the Placebo effect was demonstrated for the first time - “Such is the wonderful force of imagination!”, remarked Haygarth. Wooden Rods aren ... Read full article.