When left to your own devices, with no obligations the next morning, what time do you naturally go to bed? While I’ve managed to establish a steady rhythm for myself, waking up between 6:00 and 7:30 most days, it’s far from my natural tendency. If given the choice, I drift off sometime after 12:30 a.m.—and sleeping only six hours is simply not an option for me.

A while ago, I started reading Why We Sleep by Matthew Walker. Although I haven’t finished it yet, one key lesson stuck with me. It sheds light on why some people are “early birds,” springing out of bed at 6:00 a.m., while others are “night owls,” wide awake into the small hours of the night. Surprisingly, this isn’t entirely learned behavior.

Walker explains that our bodies have a chronotype—a natural preference for when we sleep and wake. This varies among individuals, and here’s the fascinating part: the diversity in chronotypes likely evolved as an adaptive trait. In early human societies, when people lived in groups as hunter-gatherers, synchronized sleeping left everyone vulnerable. But a mix of night owls and early risers meant some group members were always alert, reducing the risk of ambush.

Fast forward to today, and about a third of the population leans toward a late-night schedule. Unfortunately for night owls, societal norms often prioritize early starts, making it harder for them to thrive within rigid schedules. Personally, I found that maintaining a rigid sleep-wake rhythm helps in adjusting to waking up to hours that may feel unnatural at first. However, Matthew Walker seems less optimistic for the “night owls” portion of the population. I’ll keep you updated as I learn more ✨