For nearly 15 years Jim B. Tucker, associate psychiatry professor at the UVA Medical Center's Division of Perceptual Studies, has been investigating claims made by children, usually between the ages of 2 and 6 years old, who say they've had past lives.The children are sometimes able to provide enough detail about those lives that their stories can be traced back to an actual person—rarely famous and often entirely unknown to the family—who died years before.