A new study suggests being well-rested could actually be a detriment to creativity. In fact, the more tired you are, the more creative you’re likely to be.

Mareike Wieth, an assistant professor in the Department of Psychological Science at Albion College, and Rose T. Zacks, director of the Cognitive Aging Laboratory at Michigan State University, recruited 428 college undergraduate students and had them complete a questionnaire to identify whether they were night owls, morning larks, or “neutral” — somewhere in between.

Then, during morning and late afternoon sessions, the students were given six problem-solving tasks, half of which were insight problems, with the other half being analytic questions.

The study found that the students were better at solving the insight problems during the timeframe in which they said they were most tired. In other words, the night owls solved the insight problems better in the morning, whereas the morning larks had better success with them at night. The neutral group didn’t slant either way, and the analytical problems weren’t affected by the time of day at all.

Bottom line: we may have a creative advantage when we’re most tired.

The researchers said this insight could be useful to students, and even recommended they take classes like art and creative writing at their non-optimal time of day.

“Previous research has shown that students tend to get higher grades when classes are in sync with their [body clocks],” they said. “However, the interaction between time of day and type of class has not been investigated. The results of this study suggest that the relationship between time of day and grades needs to be investigated and may not simply follow a uniform pattern.”