We're all big fans of a good night's sleep - but have you ever heard of the word "chronotype" before?
Coined in the 1970s, the word literally means "time type" and is a sleep psychology concept. A chronotype is your "circadian typology", or in plain English, the individual differences in alertness and activity depending on the time of day.
"Circadian" means a 24-hour cycle, otherwise known as your body clock. It's the job of sleep psychologists to determine these natural sleeping patterns. But by understanding them ourselves, we can move toward happier, more productive lives, writes The Guardian.
Sleep is becoming a big market these days, with one in three of us experiencing sleep deprivation, and we all want to keep up with the latest rest trends, whether that's pillow sprays, meditation, or maybe a weighted blanket.
The latest theory is that there are four basic chronotypes, each with an easily memorised animal name.