It an interesting thought but hard to demonstrate or scientifically falsify. I would rather say that every single person on earth has a little of each other inside of them. Read this quote from Cloud Atlas expressing the idea:

To be is to be perceived, and so to know thyself is only possible through the eyes of the other. The nature of our immortal lives is in the consequences of our words and deeds, that go on and are pushing themselves throughout all time.

Our lives are not our own. From womb to tomb, we are bound to others, past and present, and by each crime and every kindness, we birth our future.”