Mulder: Well, on a basic cellular level, we're the sum total of all our ancestors' biological matter. But what if more than biological traits get passed down from generation to generation? What if I like sunflower seeds because I'm genetically predisposed to liking them?
Scully: But children aren't born liking sunflower seeds. Environments shape them; behavior patterns are taught.
Mulder: There are countless stories of twins separated at birth who end up in the same occupation, marrying the same kind of people, each naming their child Waldo.
Mulder: Jung wrote about it when he talked about the collective unconscious. It's genetic memory, Scully.