What If Your “Insomnia” Is Actually an Ancient Survival Instinct?

Modern life rewired sleep with electric light and industrial schedules—while your brain keeps trying to follow a far older human rhythm…

For half of my life I thought something was wrong with me because I regularly woke up in the middle of the night. Sometimes it was around one or two in the morning, sometimes closer to three.

I’d lie there staring at the ceiling, frustrated that my body refused to do what everybody said it was supposed to do, which was sleep straight through the night. I even tried sleeping pills for a while, trying to force myself into the modern expectation of a single, unbroken block of sleep. It never felt right and it never solved the problem.

But then, a few decades ago, I discovered that what I was experiencing was not a disorder at all but a very old human pattern with deep historical roots and, I believe, an evolutionary purpose. Once I learned that, everything changed for me.

Instead of fighting my own biology, I began working with it.

Before the industrial revolution and the bright electric lights that came with it, sleep looked very different for most people.

Historians digging through diaries, medical texts, church documents, and literature from medieval Europe through the early nineteenth century kept finding references to something they called “first sleep” and “second sleep.”

It turns out that people went to bed shortly after nightfall, slept for three or four hours, then naturally woke up for anywhere from half an hour to a couple of hours.

During that quiet “middle period” they prayed, wrote letters, had long conversations, made love, tended fires, checked on animals, or simply rested. Then they went back to bed for their second sleep until dawn.

This pattern was so common that it was rarely explained. Writers simply assumed everyone understood what first sleep was.

Doctors wrote about treatments that should be taken after waking from the first sleep. Priests advised using the waking period between sleeps for devotions. It was so ordinary that nobody thought to label it a problem until we started using artificial light.

What fascinates me is how universal this pattern appears across time before modern lighting. The historian A. Roger Ekirch documented references in hundreds of sources, and not just in Europe. Segmented sleep is described in ancient Greek texts, medieval Chinese medical writings, and accounts of pre industrial Africa and South America.

In other words, all over the world humans shared this rhythm.

The real anomaly is our insistence today that eight hours of uninterrupted sleep is the “normal” human state. It is not. Instead, it’s what happened when we flooded our evenings with artificial light and compressed our waking hours into a rigid industrial schedule.

We decided that nighttime was for sleeping and daytime was for working, and then we coerced our biology into fitting that mold.

Once I understood this history, my own nightly awakening suddenly seemed ordinary. What had felt like a sign of anxiety or insomnia turned out to be the leftover echo of a pattern shared by billions of ancestors over tens of thousands of years.

But the history alone was only part of what made the insight transformative for me. The piece that resonated most deeply came from thinking about why this pattern existed for so long, kind of a variation on my Hunter/Farmer theory to explain ADHD.

When I look back at the lives our ancestors lived for most of human history, it makes perfect sense that sleep would be broken into segments. Small bands and tribes lived close to the ground, surrounded by animals, unpredictable weather, and the possibility of danger.

Moving through a world like that required both rest and vigilance. Staying alive depended on maintaining a watchful presence even through the night. If everyone were fully unconscious at the same time, the group would have been vulnerable.

But if people naturally drifted in and out of sleep at different times, there would almost always be someone awake enough to hear a branch crack, stir the fire, or sense an approaching threat.

Seen that way, my habit of waking up in the dark suddenly felt like something ancient in my bones. It felt less like a flaw and more like an evolutionary safety mechanism, a built in system for collective protection.

When I wake now, I sometimes imagine that long line of ancestors stretching behind me, keeping quiet watch around their fires under the stars.

Something about that image is comforting. It makes those dark early morning hours feel gentle rather than stressful. Instead of lying there with a racing mind, I keep a book next to the bed and read for half an hour or so. Almost every time it settles me back into sleep without effort.

The moment I stopped treating the awakening as a problem, my body relaxed, and my sleep improved.

I suspect that many people experience the same pattern without realizing how normal it is.

Our “medical” modern culture has done a remarkable job of convincing us that sleep must look a certain way, and if it doesn’t, we must be doing something wrong. But when you peel back the last couple of centuries of artificial light and industrial schedules, a very different picture emerges.

Sleep is fluid. It responds to light, temperature, seasons, stress, safety, and the presence of others. It looks different in winter than in summer. It changes as we age. And for most of our history it unfolded in two natural waves, with a quiet, contemplative space in between.

Learning this allowed me to look at my own nights with new eyes. Instead of resisting my biology, I now welcome that gentle waking period as part of a rhythm far older than any modern prescription.

If you’re someone who wakes in the night and worries that something is wrong, consider the possibility that nothing is wrong at all. It may be that your body remembers something ancient. It may be that you are simply keeping watch with countless generations who came before you.