I just recently saw the movie Unleashed, starring Jet Li.
It's an interesting premis: a man is raised to be basically think and act like an attack dog. If the collar is on, he's timid and almost fearful, but when that collar is removed, and he's given a direction, he's a brutal fighter. He was conditioned from a very young age to believe that this is his place in the world.
The next part is: what does it take to make the "dog" into a man? I think the answer this movie gives is a (much) less racy version of the method used in the Epic of Gilgamesh to make Enkindu the Wild Man civilized.
For those unfamiliar with Gilgamesh, it's good reading for anyone who thinks that ancient stories are tame and boring. To summarize this little section of the epic: Enkindu is causing problems, and Gilgamesh is asked to help, so Gilgamesh's solution is to tame Enkindu by hiring a prostitute for him. Enkindu falls in love, and decides to go back to civilization.
Without getting too much into the story, I think that Unleashed is doing something similar, but the love is a bit more of an innocent form.
So, it brings an interesting question: Is love what makes us human? I'll have to think about that some more.