Most of the world isn't wired to wake at 5: Neuroscientist Yousef

Cognitive neuroscientist Sahar Yousef said population data suggests most people are naturally biphasic, with peak energy in the mid-morning, a sharp afternoon slump and a second wind after resting. She added that only about a quarter of people are natural early risers, while those with strongly PM-shifted schedules make up roughly 10% of the population.