By Linda Pressly
BBC Radio World Current Affairs
The belief that our spirit is reborn after death has been held for thousands of years but still fascinates and divides experts in equal measure. Have scientists at the "home" of reincarnation research in the US managed to prove its existence?
Nathan was born with a birthmark on his chest in the same place as his great-grandfather
The University of Virginia's Division of Personality Studies is housed in a simple, wood-frame house on the edge of the Charlottesville campus. The ring of its phones and manual typewriters evoke a bygone era but this is the powerhouse of revolutionary ideas about reincarnation.
Dr Ian Stevenson, a psychiatrist in his 80s, has spent over four decades studying thousands of children who apparently remember a past life. "I think reincarnation is the best explanation, though not the only one, for the strongest cases we have," he says.
It is a highly contentious claim. If reincarnation exists, it means the mind or consciousness can survive bodily death and continue in another life.
Hollywood recently generated more debate on the subject when Nicole Kidman played a woman who believes a 10-year-old boy is the reincarnation of her dead husband, in the film Birth. And Glenn Hoddle was sacked as England football coach in 1999 for causing offence with remarks about his beliefs.
Reincarnation does fly in the face of orthodox science, although it is a belief held by Buddhists and Hindus. Their interpretation goes further than the scientists because they believe the soul is cleansed by successive rebirths and actions in one life can impact on the next.
So have Dr Stevenson and his colleagues proved the case for reincarnation?
Some cases are from within the same family. But the most convincing examples are where a child talks about the life of a complete stranger. In Lebanon, Dr Stevenson studied the case of Imad. He found the family of the dead man he believed the boy was talking about, and took Imad to visit them for the first time.
"Imad knew where the dead man had tied his dog. And he pointed out the place where his bed had been. The deceased man had pulmonary tuberculosis, so he was isolated and his friends were only allowed to talk to him through a window. Imad knew about that."
But Dr Leonard Angel, a philosopher at Douglas College in Vancouver is suspicious of Dr Stevenson's study and says the original information the child gave his parents proved to be way off the mark.
"He [Stevenson] takes fragments of information and fits them onto another person. If you go to any town with the same degree of flexibility can you find someone else that would be as good a match? The answer is yes. There is no analysis of how you couldn't find an equally good match by going to any town."
The failure to analyse prior probabilities or carry out control experiments is a fundamental criticism of reincarnation research, and one shared by Dr Helen Joyce, a science writer based at Cambridge University.
Dr Stevenson has spent 40 years studying reincarnation
She says the scientists studying reincarnation should have ruled out the chance explanation and haven't done so. And they should drop their assumptions if they don't have supporting evidence.
Seven hundred miles from Vancouver, in the beautifully rugged region of Northern British Columbia, Dr Antonia Mills has been studying reincarnation among the Native American Gitxsan and Witsuwit'en communities since the 1980s.
She takes me to meet Mark Peters, who believes his grandson Nathan, a delightful five-year old, is the "comeback" of Mark's own father.
First someone in the family had an "announcing dream" then Nathan was born with a birthmark on his chest in the place where his great-grandfather had a scar. And according to Mark Peters, Nathan has shown an unusual local knowledge.
Dr Mills thinks this is a strong case, but concedes finding proof of any reincarnation is problematic because what constitutes proof is "culturally embedded".
Similarly, Dr Stevenson is undeterred by criticism and says: "If you are committed to scientific investigation, you can't allow yourself to be engaged in a popularity contest. You have to continue pursuing the truth."
Many Happy Returns was broadcast on Wednesday, 15 December at 2100 GMT on BBC Radio 4.