An even easier way to not act like an asshole is to be raised by parents who teach you to be thoughtful and polite by default.
We can choose how we respond to them to a degree, but we can't turn them off.
To what degree can we choose? That's an interesting question, since the machine that's doing the choosing is comprised of 50% of one parent's DNA, and 50% of the other's.
But we feel like we make choices all the time, don't we?
Certainly, we consult ourselves, and ask ourselves what we want to do. Sometimes the answer comes to us, and that's what we choose.
But where does that answer that comes to us come from? And how does it get into our consciousness?
Do you want chocolate, or vanilla?
Did an answer come to you then?
Where did it come from? And why was it what it was, and not something else?