Perceiving Charisma Stops Critical Thinking
According to a 2010 study, a person's assumptions about a speaker's charismatic abilities has important effects on the executive networks in the brain.
The more you THINK somebody is charismatic — because of the way they talk, their style, performance, or personality, — the more your rational brain shuts down.
The study was looking at Christians and their belief in charismatic healers.
The study discovered, "...the general deactivation in response to the known healer depends on the Christian participants' assumptions about the healing powers of the speaker and the efficacy of prayer."
What's happening is that the brain is sensing a situation of high trust, and is handing itself over passively to the leader: the charismatic person.