Having psychologized every other aspect of morality, there is no good reason why we shouldn’t also psychologize the idea of character.
But the core problem with David Brooks’s analysis is this: In the Victorian sense, character was not an innate characteristic you possessed, it was something that other people gave you.
Character was understood to be an aspiration, in other words, that became real by acting in such a way that others observed in you “character.”
Absent a cultural context that promotes this ideal, character in the old sense doesn’t make any sense. It doesn’t exist raw in nature as an empirical fact of human beings. It is a cultural creation, made real when people care enough to aspire to it and to incarnate it to the extent that human beings can incarnate ideals.