"Ultimately it makes them feel more real, something we thought we could do much better than we've done before. How they feel about the player does affect what they do and how they treat you, but it doesn't alter their goals, just how they may complete them. If an NPC wants to obtain something, like food, and they hate you - they very well may attack you to steal your food, depending on how aggressive their character type is (i.e., how prone are they to violence)."