ALAN ALDA (NARRATION) So Danny Povinelli sees the Human Spark – the essential difference between us and chimpanzees – in our ability for abstract thought.

DANIEL POVINELLI Chimps have concepts. They form representations of the world in their head about…representations about what’s likely to happen if I try to take that treat away from the dominant animal. OK? Jadine knows, Jadine knows what’s going to happen if she takes that treat away from Paula – she’s going to get hit. Is she aware of knowing it? Can she step back and reflect on her thoughts the way you and I can? I don’t think so. So what are some of the fundamental differences, the kind of thoughts we can have but they don’t have? I’m going to tell you my best guess. And it’s a young field – who knows what the truth is? But it seems as if chimps don’t have the ability to reason about unobservable things. They can reason about all the things in the world that they can touch, that they can taste, that they can see. But they don’t reason about abstract things like God, ghosts, gravity, that sort of thing. They don’t invent the unobservable to explain the observable.

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