I don't know about too much, but is it possible at least in part that we often mistake feelings related to reincarnation with primitive animal instinct? Many animals know exactly what to do in cetain circumstances from migration to nurturing young. were they reincarnated too, or is it old fashioned instict.
Many times human behaviour is much more "complicated" than the basic needs of animals, but could it be we were just born that way with programmed circuitry that makes us "remember" our past lives?