/cloudfront-ap-southeast-2.images.arcpublishing.com/nzme/5V3LSMBNOMA5YIYY5BFEJUMEDU.jpg)
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.
We're used to owls and roosters being symbols of night and day, but psychologists have ditched the bird metaphors. An Australian sleep expert, Olivia Arezzolo, has called the four types bears, wolves, dolphins and lions.
So, what are the characteristics of those animals? For starters, bears include half the population. They simply follow the solar cycle by getting up with the sun and going to sleep in the evening - and they tend to get sleepy right after lunch.
But if you'd rather get up late and you have more energy at night, maybe you're more of a wolf.
/cloudfront-ap-southeast-2.images.arcpublishing.com/nzme/TWH5O7WIXFUR45TPI2OVOTIGOU.jpg)
And if you start your work day early, are hugely productive in the morning, and fizzle out after midday, turns out you're more of a lion - going to bed just as the wolves are coming out to play.
Dolphins might just be the unluckiest category of them all. They're poor sleepers who find it hard to work in the afternoon and are often irritable. Arezzolo says dolphin types account for about 10 per cent of the population. They're perfect as entrepreneurs, she says, what with the short attention spans and lack of time management.
Turns out that real dolphins are very light sleepers. Only half of their brain sleeps at a time - this is called "unihemispheric sleep" - so that they can keep breathing and literally keep one eye open for predators.
And although you can't change your chronotype, less alcohol, a healthy diet, a spot of meditation and putting away your phone will improve your sleep no end, no matter what animal you identify with.