Juline

“Japanese researchers blindfolded a group of students and told them their right arms were being rubbed with a poison ivy plant. Afterward, all 13 of the students’ arms reacted with the classic symptoms of poison ivy: itching, boils, and redness. Not surprising until you find out that the plant used for the study wasn’t poison ivy at all, just a harmless shrub. The students’ beliefs were actually strong enough to create the biological effects of poison ivy, even though no such plant had touched them. Then, on the students’ other arm, the researchers rubbed actual poison ivy, but told them it was a harmless plant. Even though all 13 students were highly allergic, only two of them broke out into the poison ivy rash!”
― Chris Estes, The A.P.P.L.E. Principle