Your Body Wants to Sleep Twice — Here's Why

Added: 2026-05-21

[00:00:00]In the early 1990s, a psychiatrist named Thomas Wehr ran an experiment.

[00:00:05]>> [music] >> He took a group of people and removed all artificial light from their lives.

[00:00:09]No lamps, no screens, nothing but natural darkness for 14 hours a night.

[00:00:16]Within weeks, something remarkable happened. Every single participant naturally shifted into a biphasic sleep [music] pattern.

[00:00:24]4 hours of sleep, a quiet gap of 1 to 2 hours, then another 4 hours of sleep.

[00:00:31]But here's what made the study famous.

[00:00:34]During that midnight [music] gap, Wehr measured their brain chemistry. He found that the participants' brains were flooded with prolactin, [music] the same hormone released during deep meditation.

[00:00:45]It creates a [music] state of calm, almost trance-like wakefulness.

[00:00:50]Their brains weren't malfunctioning.

[00:00:52]They were entering a state of consciousness [music] that modern humans have almost completely lost. And here's the part that changed