In 1995, I attended the national conference of IANDS in Hartford, CT. One of the presenters was Jenny Wade, Ph D who is a research psychologist, writer, consultant and teacher (Professor, University of Santa Barbara, CA) specializing in consciousness studies, especially the evolution of consciousness. Her background is in human development with a particular emphasis on consciousness at the edges of life, before birth and after death, when the cellular basis for sustaining awareness is either severely compromised or nonexistent. Her presentation was most interesting and highly convincing.
The point of her presentation was that in interviewing very young children, in an unrelated study, she found that they had memories before birth, and even one just before conception. These memories could be verified by interviewing parents of the children, and the subject matter of the memories had not been discussed by the parents with the children, or while the children had been present. Some of the memories were of things which would have been embarrassing to the parents, and which they wouldn't have been discussing even between themselves.
Her position was that the "soul" (or whatever you would like to call it) joined with the egg at conception, loosely, and became more fixed as pregnancy became advanced, until at birth, the ties were strong. I had a copy of her book regarding this,
Changes of Mind: A Holonomic Theory of the Evolution of Consciousness, but it has apparently been lost in the several moves I have made since then. What she talks about is well worth listening to, and provides the closest thing to proof of a duality of "body/soul" that I have come across. Compelling indeed. This woman is not a kook!