Heads up, you're getting tagged if you talk about him, and yes, I will miss someone and I'm sorry for that - tag people if you want!
I just rewatched Ex Machina and I have feelings.
Okay, so Nathan has what we might call some character flaws? Ego?
He clearly lures an employee out to his home to conduct and experiment and he is less that forthright about the exact nature of the experiment and Caleb's role in it. So just his treatment of Caleb shows some...problems.
Then there's the treatment of his inventions. This is more a gray area because one could argue they are not human - that they cannot feel and think and suffer. Even if they do, Nathan may not partially or fully be aware of this fact.
He also mines data/has an inappropriate level of access to people's cell phones. Let's just leave it at that. He's not what I would call a "good" person. He's at least in the gray area, let's say.
Aside from all that, ^ observe Nathan's behavior. He has Caleb sign an NDA that is kind of insane. But it is Caleb's choice to sign it. He lives in isolation. Maybe because he's just that weird. Maybe he wants to conduct his experiments in secret. Maybe he doesn't trust anyone.
And who can blame him?
It takes like what, a day? Two? For Caleb and/or Ava to start conspiring. Ava cannot be blamed (I suppose). She is following the directives given to her. To exercise free will.
But Caleb. He is there a week. And in less than that time, he does exactly what Nathan is afraid of.
He violates his NDA.
He conspires against Nathan.
He intends to steal/release Nathan's property and trade secrets into the public.
He treats Ava more human than Nathan.
He intends to get Nathan blackout drunk and lock him inside his home with no means of escape, which will most likely lead to his death.
So it's, "Welcome to my home" to "you want me dead" in six days.
So Nathan has every right to try to protect himself. What he's afraid of is exactly what only takes days to happen. He predicts Ava will go through Caleb to gain her freedom. He underestimates what she will do to him though.
My point is, Nathan can't trust anyone and maybe that's why he acts this way. But why? Is it because something in his past or is it because he knows how vile his own actions are, and he is protecting himself from someone perhaps behaving as badly as he himself behaves?
This viewing just gave me a slightly new look at Nathan. If Nathan is a true narcissist, I don't think he could be that isolated. Narcissists have a deep self-hatred that is covered over with a false self, and they need reflections from others to reflect back an image of themselves. To do this, they need humans around them that they can manipulate, love bomb and get that "reflection" from, to inform them of who they are.
A true narcissist can't be alone, even with androids.
If he's not a narcissist, what is wrong with him? Why is he like this?
I'm not saying he's a great guy, but the exact behavior he expected from a human was what he got. It's Ava who surprised him.