Winner of a British Medical Association Book Award A Brain Pickings Best Science Book of the Year Early birds and night owls are born, not made. Sleep patterns may be the most obvious manifestation 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, Till Roenneberg shows, 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. “Internal Time is a cautionary tale—actually a series of 24 tales, not coincidentally. Roenneberg ranges widely from the inner workings of biological rhythms to their social implications, illuminating each scientific tutorial with an anecdote inspired by clinical research...Written with grace and good humor, Internal Time is a serious work of science incorporating the latest research in chronobiology...[A] compelling volume.” —A. Roger Ekirch, Wall Street Journal “This is a fascinating introduction to an important topic, which will appeal to anyone who wishes to delve deep into the world of chronobiology, or simply wonders why they struggle to get a good night’s sleep.” —Richard Wiseman, New Scientist