I suppose so. When you see someone go through a routine day in, day out it does make them appear to share similarities with NPCs. For example, take your job. It's the same routine. Same daily life that any random NPC on GTA might have. And just like those NPCs in GTA, you don't interact with them, unless they are "mission critical" (Your boss, just like your boss in the game).
Having played a fair bit of L.A. Noire recently, i decided that i would take the "truth, doubt, lie" system and see how it would work out in real interaction. The results i found were surprising. You know how whenever you call someone out with a lie on Noire, they would always demand proof, and then be able to safely deny any claims you made if you couldn't provide it? Well, that works in the real world too; someone may make a claim, and if you say something along the lines of "Oh yeah? You can't prove i was there!, you'll find out that most of the time, they can't, and you can retain some level of assurance. In fact, almost any conversation in the real world can be facilitated through the truth, doubt lie system. In using that "dialgoue choice" system in the real world, using a similar example to the one above, i have found that if you 'doubt' someone without calling them out as being an outright lie, you can get them to open up and have a higher chance of them admitting to something.
For example:
Lie
Person 1: "I know you were at that party last night."
Person 2: "You got no proof. You don't know a thing."
Doubt
Person 1: "You weren't at home last night. Were you out?"
Person 2: "Yes, i was. At a friend's house with a couple of mates"
Strangely enough, although it is initially obvious (saying someone is a liar will always spark an initial defensive reaction) it has demonstrated that being economical with your choices of 'dialogue' with people can have a profound impact with the results.
Incidentally, i've had fantasies of committing mass homicide in a similar fashion to video games. We've all done it. Those times on GTA or Oblivion or Fallout or any similar game where you just take our your gun / sword / pink dildo and start slaughtering everyone and anyone for no reason at all. Something in you just... snaps. And you don't stop until you're dead. And you think nothing of it because they're all just NPCs. I've found it all too easy to associate that thought with real people, but then i hold contempt for society as a whole anyway.
