Can you unpack the distinction you are making by the words "instinctual" and "learned"?

I didn't see anything in the wiki article that David linked, or in the references available from it, to support David's and your assertion. The material says that we know where face recognition is done in the brain. This does not bear on the question of whether it is "instinctual" or "learned". Something that would bear on the question would be information about the degree to which the ability already exists at birth (one possible unpacking of "instinctual" vs. "learned"). I have heard of other research indicating that newborn babies have some face-recognition ability, but not of any assessment of how they compare with adult ability.