If you’re more productive, alive and energetic at night, you’re an owl. Your alarm clock—if you even have one—is likely buried under a pillow. Smolensky describes a classmate who would call wake-up services, set multiple alarms to ring and blast music, yet was still unable to get out of bed in the morning. Even though he forced himself to stay in when he had morning classes, he still couldn’t fall asleep early at night—and had to drop out of graduate school. Fortunately, most owls aren’t that extreme.

Owls are best left undisturbed before they’ve had their cup of coffee. In contrast to larks, low moods typically occur upon awakening, but mid-morning and late evenings are creative peaks.

“Owls seem to be more outgoing and social,” says Smolensky, “They also tend to be risk-takers.”

Teenagers are notorious owls—at puberty, the body clock changes and even those who tend to be lark-like become more nocturnal until their mid- to late 20s, when they revert to their more usual patterns.

Though most owls are able to adjust to the 9-5 work routine, extreme night owls may feel completely out of synch in such an environment. Consider a night shift, or a job you can do from home, on your own schedule.