ES-B: What you say about the generation of the alien abduction belief in 2011 is really interesting. You suggest that the generation of the belief might be due to abductive inference as applied to sleep paralysis and hypnopompic hallucination not due to specific neuropsychological impairments. But you point out that many people who have these experiences do not adopt the alien abduction belief, and so we need a second factor, which you suggest is the alien abduction belief being compatible with things one already believes (so people who have ‘New Age’ beliefs may well be more prone to forming the alien abduction belief if they experience sleep paralysis and hypnopompic hallucination).
So this looks like the kind of thing a one-factor theorist might say about delusions more generally. What do you think the difference is between this kind of case, where the second factor consists of biases which are present in the healthy population, and the case of Capgras delusion, or other delusions, where you say the second factor is something quite different, and does not occur in the non-delusional or healthy population?
MC: Well it depends what you mean by ‘healthy population’. New Age people who believe in UFOs and so on—that doesn’t sound very healthy to me. So they’re healthy in the sense that they don’t have brain damage but they’ve got a very strange belief system, it’s very unlike most people’s belief system and if they didn’t have that belief system, then they wouldn’t become delusional.