Lol! Yeah, the caracter.
All my therapists told me the typical. You are born with a caracter and you are forming your personality according to your character and the way this is going to express itself in its interactions with the outside world.

What I know is that a child is not easily taught by words, but with acts.
So, there is also the other possibility. The parents can say a child a thousand of times that it's good to express emotions but at the same time they don't do it themselves or when the child expresses his/her emotions (s)he finds that they are censured or judged.

It's only a thought.