I've just cited an classic paper by Nicholas Spanos in a study I'm writing up, and thought it worth mentioning here because it's such an interesting set of experiments.

The set of four studies look at factors affecting the experience of past-life regression. The experimenters hypnotised participants and gave them a suggestion that informed participants that they were regressing in time, beyond their birth and into a new dimension. The suggestion ended with:

"You are now in a different life, living in another life that you have lived before in another time. You are now reliving that other life that you lived once before in a different time."

In the first study thirty-five subjects reported a past-life identity and 75 did not. Further, they found that:

"past-life reporters frequently supplied inaccurate historical information, did not possess information that might reasonably be expected of a person who actually lived in the relevant historical period, and made historical errors that would have been impossible for a person who lived in the era in question"

In the second experiment they found that varying the way in which the past-life procedure was presented, it was possible to dramatically influence the types of past life experiences that participants imagined.In the third study they investigated the relative intensity of the imagined past-lives. They found that the intensity with which participants had a past life experience predicted how strongly participants felt that they really had lived a past life.

It's a fascinating set of results. They beautifully illustrate how the experience of hypnotised participants is shaped by the suggestions the hypnotist gives, and by the beliefs that the hypnotist communicates. Someone has helpfully hosted this paper online, so you can read the full article online.

Spanos, N. P., Menary, E., Gabora, N. J., DuBreuil, S. C., Dewhirst, B. (1991). Secondary identity enactments during hypnotic past-life regression: A sociocognitive perspective. Journal of Personality and Social Psychology, 61(2), 308-320.

 Download the full article here