Dumb bitches like this piss me off.

[XIII]

You guys are over simplifying again. When a human baby is deveoping, scientists have found the point where the brain is a reptilian brain, mammalian brain, and finally... when the child is fully developed... the human brain. Our classification of "mammal" is simply because we fit the definition. And since we're not "arrogant," we didn't make a new classification.