From the ages of 2 to 6, James Leininger seemed to recall in striking detail a past life" he had as a World War II Navy pilot who was shot down and killed over the Pacific. The boy knew details about airplanes and about pilot James Huston Jr. that he couldn't have known. James' parents say he also had terrible nightmares about a plane crashing and a "little man" unable to get out. James, now 8, stills loves airplanes, but he is free of those haunting images of the pilot's death. Jim Tucker, a child psychiatrist and medical director of the Child and Family Psychiatric Clinic at the University of Virginia, is one of the few researchers to extensively study the phenomenon of children who seem to have memories of past lives. He says James' case is very much like others he has studied. "At the University of Virginia, we've studied over 2,500 cases of children who seem to talk about previous lives when they're little," Tucker said. "They start at 2 or 3, and by the time they're 6 or 7 they forget all about it and go on to live the rest of their lives." Tucker -- the author of Life Before Life: A Scientific Investigation of Children's Memories of Previous Lives -- has seen cases like James' where children make statements that can be verified and seem to match with a particular person. "It means that this is a phenomenon that really needs to be explored," Tucker said. "James is one of many, many kids who have said things like this." While about three-fourths of Americans say they believe in paranormal activity, 20 percent believe in reincarnation, according to a 2005 Gallup poll.