hey guys this is a cool topic, glad to see your juices flowing on this one, way to go frozen.
in my opinion, xenos don't have fear, they are not that intellegent. it's only the instinct of self-preservation. someone stated, they don't run away from someone with a flame thrower, but they know to back off, only after being burnt. however they will jump at the chance to kill the one holding the flame thrower if possible.
yautja, i believe do have fear, it is subtly displayed in pred 1 and pred 2. and in AvP its apparrent they do have fear. they can have complex emotions just like humans, only they deal with them better, they arent afraid to die if they have to, but will retreat from a prey if necessary only for temporary regrouping. they have the resources like strength and technology, not to mention intelligence and a strong confidence in all those advantages. all that, helps back up them up when fear arises example scar facing the queen. and city hunter facing the agents in the slaughterhouse, remember he backs away when it notices the uv light.
Clan Balatu
Struggle is The Glory