Definition of good Deeds

Doing a good deed can lead some people to more kind acts while spurring others to backslide. But how people respond depends on their moral outlook, according to a new study.

People who believe the ends justify the means are likelier to offset good deeds with bad ones and vice versa. By contrast, those who believe right and wrong are defined by principle, not outcome, tend to be more consistent, even if they're behaving unethically.

The findings were published Feb. 27 in the journal Psychological Science.

Mixed results

But other studies found just the opposite: Behaving ethically leads people to more good deeds later, said study co-author, Gert Cornelissen, a psychologist at the University Pompeu Fabra in Spain.

To sort out this conflicting picture, Cornelissen and his colleagues asked 84 undergraduates what they would do in a hypothetical dilemma where a runaway trolley is on a collision course with five people, and the only way to save them is to flip a switch, reroute the trolley and kill one person. [The 10 Most Destructive Human Behaviors]

People who would flip the switch were considered to have outcome-based morality, where the end results (saving four lives), not the actions (causing one person's death), matter most. Those in the opposite group were assumed to base their morality on rules, such as "deliberate killing is always wrong."

Those who had an ends-justify-the-means mindset were likelier to be stingier with others if they were reminded of their past good deeds and more generous if they recalled past unethical behavior. By contrast, those who tended towards rules-based morality showed the opposite trend, suggesting that past good deeds or bad deeds were prompting similar behavior later on.

In another experiment, students showed the same trends in their likeliness to cheat on a self-graded quiz. Consistent with that trend, remembering past bad deeds made people with rule-based morality more likely to cheat.

Different behaviors

For people who are keeping a mental balance sheet of their good and bad deeds, one bad act can be an offset in their minds with a nice one, Cornelissen said.