Most people, including myself, have inherited and acquired personality traits. This is mainly due to the nature of social relations and inherited traditions, and this is generally observed in developing societies, especially Islamic ones.
Personality of a person develop gradually. It does not dependent totally on wish of any person. It is not like a new dress to wear to bring a new look. It has some relation with gravity, but no relation with vanity. The lifestyle, way of thinking, morality level etc. are related with personality development. Genetically we can get figure, skin color or even to some extent intelligence which may have a little effect, but only these things can develop vanity, not personality.
Well, as much as everybody, both of them. But I believe that you are asking about the proportions, and indeed, my proportions are highly interesting. I believe in something like 20% / 80% (inherited / learned). I think that this is not the average, but it´s my case!