Dear Black People, Catching The ‘Holy Ghost’ Isn’t Real!
Basically, it’s a result of suggestibility coupled with their belief of how they’re supposed to react. Firstly, people who attend these congregations already have a bias to believe in this sort of thing (self selection). Secondly, when they are touched, or “healed”, or whatever, they are essentially being called up on stage. Once they are in this situation, coupled with their likely suggestibility, they have two options:
They could stand there and not move or do anything awkwardly, or
They can start speaking in tongues or spasm as they are expected to do.