Brainwashing has long been used to account for why otherwise reasonable people join religious groups deemed strange or aberrant from the standpoint of mainstream society. In the nineteenth century, Mormons were accused of mesmerizing people into joining them. In the 1970s, parents in the anti-cult movement abducted their own adult children and subjected them to forced “de-programming.” Today, the narrative of an individual or group being “brainwashed” by a charismatic leader persists. But is it possible to fundamentally alter a person’s beliefs despite their own better judgment?