That is one of the lessons drawn from new research at the University of Chicago Booth School of Business.
The researchers set out to determine where people draw the moral tipping point in evaluating others. How many acts must a person commit or cease before that person appears to have substantively transformed in moral character?
In a series of experiments, the researchers created characters and stories to reflect actions in everyday life. The study participants read about the actions of these fictional characters, who behaved in either a moral or immoral way.
The researchers found across all the experiments that participants were quicker to diagnose moral decline but slower to diagnose moral improvement, despite observing the same amount of evidence in each case. In other words, it is easier to become a sinner than a saint.
In one experiment, a fictional person named Barbara was described as working in an office. At times she behaved nicely -- holding the door for her colleagues or giving them a compliment. Other times Barbara cut in line or spread gossip. Participants were then told to imagine either a positive change or a negative change in Barbara's behavior.
The researchers tracked the number of weeks Barbara needed to persist in her positive or negative behavior for participants to believe that she had morally transformed. When Barbara acted badly, it took only a few such instances for the participants to judge her as having changed for the worse. Barbara didn't get any extra credit when she stopped behaving meanly, and when she tried to improve, it took many good actions for her to be seen as changed for the better.
The implications of the study go far beyond impressions of office colleagues, illuminating why people, once they have formed a negative impression of someone, can refuse to give them a second chance. The findings also raise questions for judges and public policymakers in prescribing sentencing and sentence-commutation guidelines for crimes.