In the study, the researchers looked at people in long-term relationships in which they were living with their partners. The researchers measured their beliefs about whether personality can change. They also asked people to keep a daily diary for a week. For any conflict the participants experienced, they were asked to note whether they apologized, as well as whether they took responsibility for their actions.
The researchers found that beliefs about whether personality can change did not affect whether people apologized for their actions. But the more strongly people believed that they could change, the more likely they were to take responsibility for their mistakes.