I have been an early bird for as long as I can remember. Even in college and grad school, when circumstances more or less forced me to be a night owl—even then I secretly preferred being awake and alert as the morning dawned. You genuine night owls really don’t want to know what time I’m up and about these days.

Psychological scientists are very interested in “chronotypes”—a jargony label for early birds and night owls. These preferences, or biological propensities, have important consequences, affecting school performance, work life choices, friendships, even romance. Now, it appears, our sleep and waking habits may actually shape our character, influencing our very judgments of right and wrong.

That idea comes from Christopher Barnes, of the University of Washington’s Foster School of Business, who with his colleagues* has been studying the relationship between wakefulness and ethical judgment. Previous research has suggested that people in general are more moral in the morning than they are later in the day. The theory behind this “morning morality effect” is that ethical decisions are mentally taxing, and that normal daytime activities deplete our limited cognitive resources as the day goes on. But Barnes and colleagues thought this model might be too simplistic, most notably because it fails to consider chronotype in moral calculations. If we all lose some energy throughout the day just through normal biological processes, wouldn’t being an early bird exacerbate that mental tiring? And similarly, wouldn’t being a night owl do the opposite, moderating the normal drift toward unethical choices?

The scientists decided to test the possible interaction between normal cognitive depletion and circadian fluctuations in tiredness, and the effects of this interaction on ethics. They recruited a group of volunteers to complete a five-minute problem-solving task in the morning. The volunteers were paid for each correct answer, but they were unaware that the scientists could spot, and measure, their cheating. They used a standard scale to identify each volunteer as a morning or evening person, or as intermediate. The scientists predicted that evening people—because they were not at their cognitive best in the morning—would cheat more than the morning people. That is, their morning morality effect would be counteracted by their circadian preferences.

And that’s just what they found. Evening people were much more likely to inflate their scores—to cheat—followed by the intermediate types and then by early birds. About one in five early birds cheated, compared to well over half the evening people.

In a slightly different version of this experiment, the scientists again measured volunteers’ chronotypes, and again they performed a task that offered to opportunity for dishonesty. In this study, however, some faced this challenge in the morning, others in the evening.

The findings, reported in a forthcoming article in the journal Psychological Science, provide further support for the new theory. Early birds did cheat more in the evening than in the morning—as the morning morality effect predicts—but night owls tended to cheat more in the morning. What matters, it seems, is the fit between chronotype and time of day, so that early birds are more ethical in the morning, night owls later in the day.

These findings raise questions about policies—Daylight Savings Time, for example—that attempt to dictate sleep and waking habits. And they could kindle some new interest in napping and other such interventions. Finally, Barnes and his colleagues conclude, the results may finally put the lie to the stereotype of the dissolute night owl. We early birds, it turns out, have no special claim on virtue.

*Brian Gunia of Johns Hopkins University’s Carey Business School and Sunita Sah of Georgetown University’s McDonough School of Business

Follow Wray Herbert’s reporting on psychological science in The Huffington Post and on Twitter at @wrayherbert.