Alien, I mean really Alien.

[narf poit chez BOOM]

Well, I think human emotions are logical filler for every need - that there isn't a need that you could come up with that isn't covered by a human emotion and/or a human thought process, with the exception that a human brain at our current level of thought might not reach the complexity needed, but still cover the bases. Or in other words, you can't simulate 16,000,000 atoms, even as only geometric spheres on todays computers, but that's a failure of speed and possibly memory, not basic capabilities.