Charlie introduces himself, paralleling the interaction to an anthropologist's experience in Papua New Guinea. Why? and explain more about it?

On pg. 25, Charlie discusses the appearance of an explorer, Leahy, and the stir he caused when sees by the tribesman in Papa New Guinea. The tribesman, never having seen a white man, debated on whether or not Leahy was a human or spiritual being..... their questioned was answered when Leahy was spied defecating behind a bush.

Charlie's experience parallels that of the tribesman because he is faced with the same questions about Adam. Adam looked human, acted human, and even had a personality.... what he calls a human universal, something that anthropologists would find absurd.