Ian Stevenson, a psychiatrist at the University of Virginia, began systematically investigating children who reported memories of a previous life in 1961, developing a distinctive case-study method he pursued for the next four decades: travelling to interview a child, usually between three and seven years old, who spontaneously described details of another person's life and death, then independently tracing a deceased individual whose biography matched those details, and comparing the two accounts, along with any physical marks or birth defects the child's family associated with the deceased person's reported injuries.
Most of Stevenson's roughly two thousand five hundred cases came from cultures where reincarnation was already an accepted religious premise, including India, Sri Lanka, Lebanon, Thailand, and Myanmar, which he argued made families more willing to report and discuss such memories openly. His 1966 monograph Twenty Cases Suggestive of Reincarnation established the method's template, and he continued publishing case collections and theoretical work until his death in 2007, after which his University of Virginia division, now the Division of Perceptual Studies, has continued the research under his successor Jim Tucker.