rarely elsewhere, seems to indicate that cultural conditioning (rather than reincarnation) generates claims of spontaneous past-life memories." Further, Ian Wilson pointed out that a large number of Stevenson's cases consisted of poor children remembering wealthy lives or belonging to a higher caste. In these societies, claims of reincarnation have been used as schemes to obtain money from the richer families of alleged former incarnations. Robert Baker asserted that all the past-life experiences investigated by Stevenson and other parapsychologists are understandable in terms of known psychological factors including a mixture of cryptomnesia and confabulation. Edwards also objected that reincarnation invokes assumptions that are inconsistent with modern science. As the vast majority of people do not remember previous lives and there is no empirically documented mechanism known that allows personality to survive death and travel to another body, positing the existence of reincarnation is subject to the principle that "extraordinary claims require extraordinary evidence". Researchers such as Stevenson acknowledged these limitations. Stevenson also claimed there were a handful of cases that suggested evidence of xenoglossy, including two where a subject under hypnosis allegedly conversed with people speaking the foreign language, instead of merely being able to recite foreign words. Sarah Thomason, a linguist (and skeptical researcher) at the University of Michigan, reanalyzed these cases, concluding that "the linguistic evidence is too weak to provide support for the claims of xenoglossy." Past life regression Some believers in reincarnation (Stevenson famously not among them) give much importance to supposed past-life memories retrieved under hypnosis during past life regressions. Popularized by psychiatrist Brian Weiss who claims he has regressed more than 4,000 patients since 1980, the technique is often identified as a kind of pseudoscientific practice. Such supposed memories have been documented to contain historical inaccuracies originating from modern popular culture, common beliefs about history, or books that discuss historical events. Experiments with subjects undergoing past life regression indicate that a belief in reincarnation and suggestions by the hypnotist are the two most important factors regarding the contents of memories reported. The use of hypnosis and suggestive questions can tend to leave the subject particularly likely to hold distorted or false memories. Rather than recall of a previous existence, the source of the memories is more likely cryptomnesia and confabulations that combine experiences, knowledge, imagination and suggestion or guidance from the hypnotist. Once created, those memories are indistinguishable from memories based on events that occurred