The Four Chronotypes (Dr. Michael Breus Model)
Sleep psychologist Dr. Michael Breus popularised a four-animal model that maps chronotypes to practical scheduling: Lions (15%): Early risers, most productive before noon, need to be in bed by 10 PM. Bears (50%): Follow the sun, most productive mid-morning, natural sleep from 11 PM–7 AM. Wolves (15%): Evening types, most productive at night, difficulty before 10 AM. Dolphins (10%): Light sleepers with irregular patterns, often described as insomniacs.
The most scientifically validated chronotype assessment is the Munich Chronotype Questionnaire (MCTQ) developed by Professor Till Roenneberg. It uses mid-sleep point on free days (days without an alarm) as the primary measure — more objective than subjective preference questions.
What Your Chronotype Tells You
Your chronotype determines: when melatonin naturally rises and falls, when your core body temperature is at its lowest (sleep initiation signal), when your cortisol awakening response peaks (optimal waking window), and when your prefrontal cortex is at peak function (best time for complex cognitive work).
Using Your Chronotype Result
Lions: Target 9:30–10 PM bedtime. Best cognitive window: 8 AM–noon. Schedule important decisions and creative work in the morning. Social events: accept that evenings will be low energy — own this, it is not anti-social, it is biological.
Bears: Target 10:30–11 PM bedtime. Best cognitive window: 9 AM–1 PM. You have the most schedule flexibility of any chronotype — standard 9–5 largely aligns with your biology.
Wolves: Target midnight–1 AM bedtime. Best cognitive window: 4–9 PM. If your schedule permits, shift meetings and creative work to afternoon. Use aggressive morning light protocol to manage early obligations.
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Find your chronotype using the quiz in our sleep calculator and get personalised schedule recommendations.
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