How do the Xenomorphs from the Alien movies...

...decide which humans to kill and which ones to let live to use as hosts for facehugger? In the first one, the alien just seems kill all of them. I know there's a deleted scene where one of the guys is "cocooned" against a wall, but this doesn't even make much sense as there was no alien eggs or Queen alien on board. I guess that's why they deleted the scene. On top of that, do they just have some sort of "instinct" to essentially work for the Queen Alien? Would the dog alien from the third one have the same instinctual thinking and do the Queen Alien's bidding, or is it too genetically far removed from the human xenomporphs to do so?