And for most of human history that didn’t matter — since night owls could protect their tribes from nocturnal predators or their cities from cunning conquerors — but society has MADE it a ...

They focused on "night owls", whose bodies drive them to stay up late into the night. Techniques used included consistent bedtimes, avoiding caffeine and getting plenty of morning sunshine.

Researchers scanned the brains of night owls with a bedtime of 02:30 and a wake time of 10:15, along with early risers. The tests - performed between 08:00 and 20:00 - found night owls had less ...