How much sleep does Chris Barnes say adults need, on Hidden Brain?

Chris Barnes, a sleep researcher at the University of Washington, says most adults need between seven and nine hours a night, and that hearing "seven" as the safe floor is a mistake because some people need nine. School-age children need about ten hours or more. He says almost everyone sleeping six hours needs more, and he calls the belief that you are a short-sleep exception who can thrive on four hours an unfortunately common myth.

• Barnes measures sleep by both duration and quality, and quality depends on reaching deep N3 non-REM sleep.
• A rough sign of deep sleep, he says, is that it is hard to wake you from it.
• Barnes's research finds late-night phone use cuts sleep and lowers engagement at work the next day.

Source: our own transcription of the episode. The full conversation is on Hidden Brain (2026-10-19). Read the whole episode summary →

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