It's a commonly held belief that before artificial lighting, human sleep was 'naturally' divided into two distinct periods, but how true is that?

When we sleep, we sleep right? Who knew that there were actually three different types of sleep schedules or patterns? Let me explain. While two of them are generally mainstream, the third one feels ...

For hundreds of years, night didn't mean a long sleep. Long before electric lights lit up homes and streets, people lived their lives according to the natural rise and fall of daylight. People changed ...

When it comes to body clocks, researchers should investigate the phenomenon of “second sleep”, or biphasic sleep. This is fairly well-known historically and among some anthropologists. It seems to ...

Previous to the mid-1800s, many Americans slept in what’s referred to as biphasic fashion. That is, they would fall asleep around dusk, wake up a few hours later for a couple hours, and then sleep for ...

At first I dreaded having to investigate the history of sleep. Human slumber appeared impervious to time and place, stubbornly immune to the element of change animating most works of history. My own ...