Many children spontaneously report memories of 'past lives'. For believers, this is evidence for reincarnation; for others, it's a psychological oddity.
But what happens when they grow up?
Icelandic psychologists Haraldsson and Abu-Izzedin looked into it. They took 28 adults, members of the Druze community of Lebanon. All of the participants had been interviewed about their past life memories by the famous reincarnationist Professor Ian Stevenson in the 70s, back when they were just 3-9 years old.
Did they still 'remember'? Most of them thought they did:
Twelve of the 28 participants are sure that they still have clear memories of their past life, and an additional 12 believe that they still have some of their childhood memories, so 86% of our sample still report some memories of a past life... one man was not sure about the source of the memories, two remembered speaking of past life memories as a child, but do not have these memories now, and one thought she might only remember something of her past life because these memories were much talked about in her family.
However - it turned out that they weren't always the same memories they'd originally reported.
As children they reported on average 30 distinct memories of past lives. As adults they could only remember 8, but of those, only half matched the ones they'd talked about previously:
This indicates that half of the statements remembered today are either fictional or distortions of the original childhood memories, or that the old lists of statements might have been incomplete.
In other words, they probably suffered from a false memory of a false memory - the mind is weird. Despite this, past lives seemed more memorable than real early-childhood:
We asked our participants what they remembered from their preschool years. We were surprised how little they remembered, and some could not remember anything. Our general impression is that past-life memories are better remembered into adult life than are normal memories from preschool years.
There was no evidence that these people suffered from any particular psychological problems as a result of their experiences, but 21% did say that overall, they preferred their past lives to their real ones.
Personally, I have a very vivid memory, not of a past life per se but rather of a very early stage in my own: I remember lying in my cot, unable to get out, rather bored, and waiting for my parents to get me up for the day.
This may really be my earliest memory, but the more I've thought about it, the less likely it seems. Could I have known what time it was, and that my parents would eventually come, when I was unable to even stand up by myself?
Maybe. But maybe it was just a later childhood dream about being a baby that seemed real. At that age, the line between dreams and reality is blurry as parents who've had to comfort a child after a nightmare will attest. I suspect this accounts for many of these 'past lives'.
Haraldsson E, and Abu-Izzedin M (2012). Persistence of "past-life" memories in adults who, in their childhood, claimed memories of a past life. The Journal of nervous and mental disease, 200 (11), 985-9 PMID: 23124184