Most people know, instinctively, whether they are morning people or evening people. Some are hit with a wave of dread whenever they hear a stranger’s iPhone clanging out the same ringtone as their morning alarm. Others can be found yawning into their second beer at 10 p.m. on a Friday. (For those who aren’t sure, countless online questionnaires can tell you whether you should be catching the worm or not.)
Our chronotypes are largely a function of when our bodies start and stop producing melatonin, the sleepiness hormone. Elementary and middle schoolers tend to be early risers, but productivity begins to shift to later in the day as people enter their teens and early 20s. Over time, the body slowly returns to its early-bird state. By the time we’re senior citizens, we’re back up and at Denny’s before 7. Most research suggests that people perform best on various tasks at their “optimal” time of day. The brain is sharper, it’s thought, when the body is fully awake.
But it turns out there are some tasks that benefit from a mind that’s slightly groggy. In 2011, Mareike Wieth, an associate professor of psychology at Albion College, invited about 428 students to take a series of tests in her lab at either 8:30 a.m. or 4 p.m. She first gave them the Morningness-Eveningness Questionnaire, and consistent with general trends in age and wakefulness, there were only 28 morning people among them. The participants then tried to solve several problems. Some of these were analytical, like math problems you might see on the SAT. (One example: “Bob’s father is 3 times as old as Bob. They were both born in October. 4 years ago, he was 4 times older. How old are Bob and his father?”) Others were insight-based, characterized by a problem that seems unsolvable until an “aha” moment dawns. (“A dealer in antique coins got an offer to buy a beautiful bronze coin. The coin had an emperor’s head on one side and the date 544 BC stamped on the other. The dealer examined the coin, but instead of buying it, he called the police. Why?”)