On the benefits of self-control over self-esteem, from Jean Twenge:
Cross-cultural studies provide a good example of the benefits of self-control over self-esteem. Asians, for example, have lower self-esteem than Americans. But when Asian students find out that they scored lo on a particular task, they want to keep working on that task so they can improve their performance. American students, in contrast, prefer to give up on that task and work on another one. In other words, Americans preserve their self-esteem at the expense of doing better at a difficult task.