I have a feeling that describing what it is to be human is as difficult as thinking about higher dimensions. It may be beyond our imagination.
Maybe it makes more sense to speak of when we are human. When are we doing higher level activites that animals don't do? And who knows if that is really being human. Are we human when we love but not when we hate? Are we human when we resolve our differences peacefully rather than with war? Somehow I think of love/hate and peace/war as human characteristics, for they have prevailed throughout our history.
We behave like other animals much of the time. We are hard-wired, it seems, to fulfill certain instinctual needs. But we do a couple of things that other animals may not do: understand and create.
A dog hears a noise outside and runs to the window to investigate. He sees a cat and scares it out of the yard. So the dog did gain understanding and created change (the cat leaving) in its environment? Is this what we do when we tackle the challenges of our lives. Do we ever move to high levels? How about when we do art? Or are we just a different model of computer with a different processor and operating system?
I don't know? Can anyone help here?