The myth of the 8-hour block: Why modern sleep is a recent invention

For most of human history, “8 hours of uninterrupted sleep” didn’t exist. If you find yourself waking up at 2:00 AM feeling wide awake, you aren’t broken – you’re likely experiencing a biological echo of your ancestors.

1. The Historical Reality: “First” and “Second” Sleep

Before the 19th century, humans practiced Biphasic Sleep. Historian A. Roger Ekirch, who spent 16 years researching this, discovered over 500 references in old diaries, medical books, and literature to “First” and “Second” sleep.

• The Pattern: People would sleep for 3–4 hours, wake up for a “Watch” (an hour or two of quiet activity), and then return to sleep for another 4 hours.

• The “Watch”: This midnight window was highly productive. People used it for reading, prayer, intimacy, or even visiting neighbors. In 1690, a French physician noted that this was the time when people “truly reflected on their lives.”