RACHEL MARTIN, HOST:

We're going to spend the next few minutes talking about a controversial theory about living and dying and living again: reincarnation. It's long been a central tenet of certain spiritual traditions but it's not an experience that's been rigorously tested by many scientists. Enter Jim Tucker. He's a professor of psychiatry and neurobehavioral sciences at the University of Virginia and he is doing exactly that - testing claims of reincarnation, especially those made by children. Dr. Tucker joins us from the Virginia Foundation to talk about the science behind this phenomenon. Thanks so much for being with us.

DR. JIM TUCKER: Thanks very much for having me.

MARTIN: When did you first begin to get interested in this, in the idea of reincarnation as a ripe subject for scientific inquiry?

TUCKER: Well, I got interested in it in the late '90s, but this work has actually been going on at the University of Virginia for 50 years. Over the decades, we've now study our 2,500 cases of children who report memories of past lives. And what we try to do is to determine exactly what they have said and what's happened and then see if it matches the life of somebody who lived and died before. Once I got involved, I began to focus on American cases. I have explained in this new book that I have out, and really some of the American ones are quite compelling.