Early birds and night owls are born, not made. Sleep patterns are the primary result of the highly individualized biological clocks we inherit, but these clocks also regulate bodily functions from digestion to hormone levels to cognition. Living at odds with our internal timepieces can make us chronically sleep deprived and more likely to smoke, gain weight, feel depressed, fall ill, and fail geometry. By understanding and respecting our internal time, we can live better. In this episode we interview Till Roenneberg, professor of chronobiology at the Institute of Medical Psychology at LMU in Munich, Germany, and author of the book, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired. ____ "We don't even know how much sleep somebody needs. We can calculate how much sleep someone gets, but we don't know if it's the amount they need. And we know there is a genetic individual difference between how much sleep people need." - Till Roenneberg Quotes from Till: What we learn in this episode: What is chronobiology? What is the difference between a night own and an early bird? Is it genetic or environmental? The science behind out circadian rhythm. How can you adjust your circadian rhythm? Resources: Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired Twitter: @TillRoen  https://www.youtube.com/watch?v=t5ylqK-aPX8 Get the F.Lux software we discussed -- This episode is brought to you by: Igloo: Go to igloosoftware.com/smartpeople to use Igloo for FREE with up to 10 of your favorite coworkers or customers! Lynda.com: Do something good for yourself in 2015 and sign up for a FREE 10-day trial to Lynda.com by visiting Lynda.com/smartpeople. Learn more about your ad choices. Visit megaphone.fm/adchoices