This notion of passing to me relates to an innate sense of survival, the kind of survival that often requires imitation or a change in form, much like a chameleon changes it's appearance to imitate its surroundings.
Passing also requires negotiation. Negotiating society's ever changing values. Negotiating what we inherit and what we absorb from our environment.
Some associate passing with deceit, this is something to bear in mind. Is it deceit? Is it survival?