For anything that produces something, there seems to be a set of underlying rules that shape that something.
In language we call that grammar: The grammar produces sentences.
In food, cuisine: Cuisine generates dishes and recipes.
In us, we call that personality: Our personality generates behaviours.
It is telling that grammar in language still produces non-sensical sentences. And cuisine shapes differently under every pair of hands.
And yet: We hold firmly to personality as the one thing that stays consistent.