Define "Human"

So you're saying if I showed you a dead human body, you would not say "That's a human body". Because to you, it isn't human? I'm sorry, but that's completely idiotic.

Homo Sapiens. The human species. The definition itself, of 'Human', is: A human is a member of a species of bipedal primates in the family Hominidae (taxonomically Homo sapiens—Latin: "wise man" or "knowing man").
Biologically speaking, it is our brain that allows us to think. To reason. To learn. Everything that is truly human is in our brain, and our brain is a biological component of our being. Our identity is inherently biological, and any "soul" matter you might propose we have is nothing but a back-up, or the 'spark' of life.

All humans have natural instincts, natural tendencies and natural inclinations. Heredity. Our genetics determine the leaning of our tastes, our physical capability, our inevitable size and appearance and to some degree our ability to reason and think. However, if the period in which our brain absorbs the most, from infancy to about the age of 13, is missed then by all means it's going to be much, much harder to absorb one from isolation into communal society. Children born isolated, not even feral, display the same ineptude. It is our community that allows us to cultivate such things, and all that was necessary was the development of community alongside our brain, not even "divine intervention".

If anything, this fact supports the biological identity versus the soul identity, because if the soul identity were true this should not be the case.