In a sense, tickling makes you laugh has nothing to do with tickling, and tickling does not allow one to experience pleasure. The fact that scratching makes you laugh is really just a very similar reaction to pleasure. For people who are afraid of itching, scratching is an unpleasant experience. There are many ways to explain why this reaction occurs.1. Reflex principle: scratching will laugh is by reflex, a self-protection mechanism designed by humans during the evolutionary process. The human body has many sensitive nerves in the armpits or neck, when others touch these locations, these nerves will be very nervous, send a distress message to the brain, in the brain’s instructions people will laugh, and not the itch signal through the nerves to the brain; 2, the psychological cognitive conflict and dissipation: scratching when the brain perceives the “itch “, a danger signal, is nervous, and then judges through other senses that it is just a joke, and there is a psychological cognitive conflict and dissolution that brings about suppressed laughter, and therefore is not caused by the itch itself. In any case, the reason we laugh when we are tickled is not really the joy we feel from the tickling, but a stressful physical and psychological reaction that arises in the course of social processes.