A new study suggests that you can. But not for too long.

Northwestern University psychologists found that those who perceive themselves as too good are actually more likely to act immorally as a result.

The study refers to this bad compensatory behavior as moral licensing, and researcher Sonya Sachdeva likens it to how people reward themselves with a calorie-laden cupcake after exercising.

“If I run an extra mile in the gym, I feel compelled to eat more,” Sachdeva said. “Even though I don’t deserve it, I feel like I do.”

Previous studies have not accounted for this moral licensing behavior, focusing instead on moral cleansing or how people perform good deeds to make up for past trespasses. The Northwestern study, published in the journal Psychological Science and is co-authored by Rumen Iliev and Douglas Medin, is the first to conduct tests to look into both processes. Overall, the researchers conducted three experiments with 131 participants.

In one experiment, 39 subjects were randomly assigned to either a positive-traits group or a negative-traits group. Those in the positive-traits group were instructed to write self-revelatory stories with words such as kind, caring and generous to make them feel good about their moral self-worth. Those in the negative-traits group, on the other hand, were instructed to write self-revelatory stories with words such selfish, dishonest and cruel to make them feel bad about their moral self-worth. Finally, to test if the subjects would compensate for this manipulation of moral self-worth, they were asked for donations to a charity of their choosing.

Another experiment used the same technique but tested for the effect on environmental conservation behavior instead of altruism.

The results revealed that the people who felt bad about their moral self-worth were more likely to be generous and environmentally responsible, while the people who felt good about their moral self-worth were more likely to behave the opposite way. “They didn’t need to prove to themselves how good they were,” Sachdeva explained.

More importantly, the results confirmed the researchers’ larger hypothesis that each person has an ideal level of moral self-worth—one that he will strive to maintain through compensatory behaviors when threatened.

“The study speaks to the importance of self-concept in moral regulation,” said Chen-Bo Zhong, a University of Toronto professor and ethics specialist. “People have a desired moral self-image [that they are motivated to reach].”

Loyola University Chicago theology professor John McCarthy is concerned, however, that the study takes an overly narrow look at morality.

“Moral choice differs in relation to stage in life,” he said. “The study does not indicate a concern about this, but seems to suggest that the sample group represents moral decision-making as a whole.”

To address such limitations, the researchers are considering further investigation, noting that this initial study was just a starting point.

“We were interested to study the basic psychological mechanism, and to just find the effect and to describe the effect,” Iliev said. “In the real world, it might play out differently.”