Are you sleeping enough to recharge your brain?

If the world’s most famous creative geniuses had one habit in common, would you try to follow it yourself? Well, it seems many of them did–they got seven to nine hours of sleep every night. That observation is based on a chart created by RJ Andrews, a data visualization expert and founder of the information graphic studio Info We Trust.

The chart breaks down how 16 of the most famous geniuses ever to live spent the 24 hours in their days. The geniuses included Charles Darwin, Sigmund Freud, Charles Dickens, Benjamin Franklin, and Maya Angelou. Other than Angelou, all of the geniuses were White men. And–with the exception of Wolfgang Amadeus Mozart–all got between seven and nine hours of sleep a night. The information in the cart was drawn from the book Daily Rituals by Mason Currey, which explores the daily habits of 161 geniuses from many different backgrounds, as drawn from their journals and interviews and from writings about them.

It’s not clear how many of the geniuses in the book got a good night’s sleep every night, but I’m willing to bet that Andrews’s chart is representative of most of them. Science tells us there’s a very real connection between creativity and sleep, and sleep has proven benefits for pretty much every aspect of brain function. If there’s one thing every genius needs, it’s a well-functioning brain.

Interestingly, although the geniuses slept an average 7 hours and 15 minutes a night, it didn’t seem to matter whether they went to bed late and got up late, or went to bed early and got up early–or even had a sleep routine that can only be described as bizarre. The French novelist Honoré de Balzac slept from 6 p.m. to 1 a.m., with an additional 90-minute nap at 8 a.m.

Aside from the importance of sleep, what else can we learn from these geniuses’ daily habits? For one thing, 10 of the 16 geniuses made it a daily habit to take at least one walk, and sometimes more than one. Charles Darwin, for example, took three walks a day (at least one of them with a fox terrier). Here again, research confirms that walking has benefits for mood and brain function, particularly if you do it in any sort of natural setting.

But if you step back for a moment and consider the bigger picture, there’s something even more striking that all of them have in common, along with many more of the geniuses in Currey’s book–they all had strict daily routines. We at Inc. write frequently about daily habits and routines, and for good reason. Neuroscientists tell us that our brains are at risk of decision fatigue–every decision we make, large or small, taxes our brain function even if we’re not aware of it. This is why Mark Zuckerberg’s and Steve Jobs’s habit of wearing the same outfit every day is less crazy than it sounds–it takes one daily decision out of the equation.

Decision fatigue is one reason that developing daily habits and routines can be such a powerful thing to do. The more we put our daily work habits–and life habits, too–on autopilot, the more energy our brains have for more challenging and meaningful cognitive tasks. And if you put some thought into your routines when you first create them, they can help you stick with healthy habits such as a daily workout or nutritious breakfast.