Question 1

What are the 4 chronotypes?

Accepted Answer

The four chronotypes defined by Dr. Michael Breus are: Lion (early risers, 15% of people, peak performance in morning), Bear (follows the solar cycle, 55% of people, peak mid-morning), Wolf (night owls, 15% of people, peak performance in evening), and Dolphin (light sleepers, 10% of people, often anxious, irregular schedule). Each chronotype has a distinct ideal sleep schedule and peak performance window.

Question 2

What is a chronotype?

Accepted Answer

A chronotype is your biological predisposition to sleep and wake at certain times. It is largely determined by genetics and the PER3 gene, and affects when you feel most alert, when your core body temperature peaks, and when hormones like cortisol and melatonin are released. Chronotype changes throughout life — children tend to be earlier, teenagers shift dramatically later (a biological shift, not laziness), and adults gradually shift earlier again after age 20.

Question 3

Am I a Lion, Bear, Wolf, or Dolphin?

Accepted Answer

Take the 8-question chronotype quiz on this page to find your type. As a guide: Lions wake before 6:30 AM naturally and do best work before noon. Bears follow the sun and peak around 10 AM. Wolves struggle to wake before 8 AM and peak in the evening. Dolphins are light sleepers with inconsistent patterns who often feel unrested.

Question 4

Can I change my chronotype?

Accepted Answer

Your core chronotype is mostly genetic and cannot be fundamentally changed. However, you can shift your sleep timing by 1–2 hours using consistent sleep schedules, morning bright light therapy, and avoiding blue light at night. Night owls forced to maintain early schedules suffer social jet lag — a chronic mismatch between biological and social clocks that impairs health similarly to regular shift work.

Question 5

What is social jet lag?

Accepted Answer

Social jet lag is the mismatch between your biological sleep time (chronotype) and your required social schedule. For example, a Wolf chronotype forced to wake at 6 AM for work experiences the equivalent of weekly jet lag. Research links chronic social jet lag to higher rates of obesity, depression, cardiovascular disease, and metabolic disorders.

Question 6

What chronotype is most common?

Accepted Answer

Bear is the most common chronotype, accounting for approximately 55% of the population. Bears follow the solar cycle naturally, feeling sleepy after dark and waking with daylight. Lions and Wolves each represent about 15%, while Dolphins make up roughly 10% of the population.