Roger Ekirch's 200-Year English Sleep Pattern Isn't Ancient Human Nature

David Samson argues in The Sleepless Ape that modern insomnia is not a new dysfunction but the inevitable collision between our ancestral sleep architecture and electric light.

We evolved to sleep in two distinct segments, separated by an hour or two of conscious wakefulness. Industrial civilization compressed that natural biphasic rhythm into monolithic eight-hour blocks, and now our bodies protest.

The diagnosis feels airtight because it rests on what appears to be historical fact. Roger Ekirch's foundational 2001 research. Anchors the entire segmented-sleep hypothesis, relies on references to "first sleep" and "second sleep" in literary sources spanning exactly 200 years (1500-1700) from a tiny literate European population.

A historian finds diary entries and period texts mentioning the sleep pattern, and suddenly that pattern becomes ancestral human nature. What's unstated is the assumption that a documented behavior in Renaissance England reflects the sleep architecture of humans across continents and millennia—it doesn't. It reflects what a specific population did during a specific economic moment, when candles were expensive, artificial lighting was scarce. Rural life allowed flexible scheduling.

If segmented sleep was not universal among preindustrial humans but rather a contingent practice in one place during one era, then Samson's entire explanatory framework collapses. We wouldn't be dysfunction-stricken creatures fighting our ancient programming. We'd be creatures adapting to an environment we designed, sometimes badly. You stop treating sleeplessness as a flaw in your neurology to fix and start treating it as feedback about the system you built. You're actually equipped to redesign. That distinction transforms exhaustion from something you endure into something you can interrogate.