In 2001, French tested the effects of crystal healing with the results suggesting that they are largely placebo effects. 80 volunteers were given a questionnaire to gauge their level of belief about paranormal phenomena. Later they were given what they were told was a genuine crystal, and asked to meditate for 10 minutes and then report the sensations they experienced. Half of the subjects had actually been given fake plastic crystals instead. French found no difference between the feelings reported between the two groups.