Xenomorphs and fear - question.

I know this post should probably go on another forum but here goes... Are Xeno's capable of the emotion of fear? I remember the scene in Alien Resurrection where the alien is in the confinement room and Brad Douriff's character stops the Xeno dead in it's tracks by placing his hand over the big red button that controlled the freezing gas (I presume it was ultra-cold nitrogen). Was the reaction by the Xeno associated with the feeling of emotion? Thanks.