I'm rewatching it now(30 minutes in to the story so far). In the scene where the hologram of Weyland is informing the crew of the mission he introduces David the android as being the closest thing that he has to a son (to the annoyance of his real daughter Vickers played by Charlize). We see David give a slight smile at this comment. He in the next sentences states that David won't appreciate something because he hasn't got a soul. This David looks to be less than happy to hear.
It would seem that Ridley Scott wants us to believe that David experiences emotions. He feels in other words. There is another telling scene where they arrive at the planet and as David is putting on the space suit the male scientist Holloway asks him why he is putting on a suit since he doesn't breathe. David explains that "you people" designed him to act like them because it makes humans more comfortable to be around their own kind. Holloway says he hopes they didn't make him too much like a human. David replies "No. Thank goodness.". The terms 'you people' and the Thank goodness are meant to indicate that although like humans, David sees himself differently and is glad that he isn't human.
Recall the shots of David riding a bicycle and throwing a basketball through the hoop. We are meant to be aware that David is in many ways far superior to us. Ridley Scott is positioning David via the script and the directing to be a protagonist and antihero. David can be seen putting one of the metal cylinders containing the killer embryo into a bag and bringing it back to the ship. Let's say that he doesn't yet realise what is in the cylinder, but when he does realise that it wants to kill humans, all of them, and there are tens of thousands of the embryos, then he considers a world without humans if he can get them back to Earth.
Like Frankenstein's monster, the creation turns on it's creator.
