For Aristotle, character and ethical culture (named respectively by the two related Greek words éthos and ethos) — including what Brandom would call our constellation of commitments and what Hegel would call our self-consciousness — build on hexis. The latter is most commonly translated as habit. Earlier, I called it emotional constitution. It is an acquired, active disposition to respond or act in certain ways that seems to be centered in the emotions. A good hexis is characterized by what we might call emotional intelligence.
Actions, reactions, and choices — as well as many things that just happen to us — cumulatively contribute to the formation of a more long-term emotional constitution that then becomes directly responsible for the tone of our responses to things, and that we can only change with major, prolonged effort, if at all. This, I believe, is the main basis of common-sense personal identity.
People respond to situations based on a combination of emotional disposition (hexis), their constellation of commitments and self-consciousness (ethos), and deliberation and choice. It does not generally make sense to blame someone for acting in accordance with their acquired disposition, but at a broader level, people are partly responsible for the formation of their disposition. People are responsible for their choices, unless they are coerced or misinformed. People are in principle responsible for their commitments; bad commitments usually involve more than simple misinformation. But misinformation, lack of good opportunity for learning, and emotional disposition should certainly be taken into account in charitable interpretation of commitments, too. (See also Willing, Unwilling; Second Nature.)