How and when we sleep is important. It’s what separates us from our nearest biological relatives – primates. We sleep for fewer hours than they do, but our REM (rapid eye movement) cycle is longer.

This evolution in our sleep pattern was just as important as the discovery of fire in giving us an edge over the animal kingdom. Sleeping shorter hours meant that ancient humans were less likely to be attacked by predators. Staying awake for longer gave them more time to perform tasks and learn new things, enabling society to develop.

Today, plenty of us push that notion to its limits in a bid to tick off more things on our to-do lists. We overcome afternoon lulls in energy with the help of caffeinated drinks, sugary snacks, or perhaps an invigorating walk or exercise class during lunch (if we actually take a break to eat one).

In the Western world, few people consider re-charging their batteries by taking a nap. Back in the 1990’s the American social psychologist, Dr James Mass, coined the term “power nap” to illustrate the benefits of one.

A number of famous companies, often tech giants like Google and Facebook, have sleep pods for their staff. But the reality is that across much of the Anglo-speaking world, afternoon naps are viewed as something for babies and old people.

Anyone else is either luxuriating in one on holiday, or is somehow lacking in dynamism. However, that’s not yet the case in many Eastern societies.

Taking a nap is still deeply rooted in the culture. In tropical countries it’s also dictated by the sun: getting up early to do activities before it gets too hot and then resting half way through the day when it’s at its most intense.

In Japan, napping is known as inemuri (sleeping while present). In Vietnam, it’s ngủ trưa (sleep at noon) and in China there’s a famous saying: “zhongwu bu shui,” which translates as “no nap at noon, collapse in the afternoon”.

Across East Asia, it’s common for workers get their mats out and sleep under their desks for up to an hour after lunch, the office blinds drawn and the lights dimmed. The Chinese become accustomed to it at school.

It’s similar in South Asia. In Bangladesh and parts of India, sleeping after lunch is called bhaat-ghoom (rice sleep). For Muslims, it’s Qaylulah (the Prophet Muhammad was a keen advocate).

Ayurvedic practitioners call it vamkukshi, or sleeping on the left side. Some of the health benefits are said to include: better digestion, improved liver and kidney function, plus reduced pressure on the heart.

Napping is also recommended in the world’s first medical text, the Huangdi Neijing (Canon of the Yellow Emperor), written 2,000 years ago. This states that wu (lunch and a nap) should take place between 11am and 1pm (based on waking at 5am)`.

The text forms the basis for Traditional Chinese Medicine (TCM), which breaks the day into 12 meridians, each corresponding to different parts of the body that are active in two-hour blocks. The lung meridian, which is responsible for moving qi (energy) around the body, is weakest at ‘wu o’clock’.

This is also the time of day when the body moves from its yang to yin state. This transition is an important time to rest and retain harmony.

In the Western world, the 24-hour body clock operates on a cycle known as the circadian rhythm. Everyone knows that keeping it in balance is important to long-term health, but sadly it’s all too easy to easy to let our busy modern lives take precedent.

There are plenty of scientific studies showing why taking a nap can do wonders for our health and wellbeing. Here are some of the main ones:

1. Boosts alertness

A famous study by the US space agency, NASA, discovered that pilots who took a nap raised their alertness by half.

2. Stimulates creativity

In 2012, scientists from Georgetown University studied how the right hemisphere of the brain remains active during a nap. They concluded that the brain is in housekeeping mode, classifying information and consolidating memories.

As the right hand side of the brain is associated with creativity, this cleansing process frees the mind to come up with new ideas on re-awakening.

3. Improves performance

Another finding of the 1995 NASA study was a one third performance boost post nap.

A study by the University of Dusseldorf also concluded that we begin processing memories the moment we fall asleep. After a six-minute catnap, study participants had better word recall than those who hadn’t had one.

4. Sustains health

Numerous clinical studies show that naps have all-manner of health benefits from strengthening the immune system and lowering blood pressure, to reducing the risk of heart disease and strokes.

5. Lifts mood

The simple act of falling asleep is one of nature’s best off-switches when it comes to relieving stress and breaking negative thought patterns.

So what’s the best way to nap?

Find a quiet space, dim artificial lights and block out the natural one. Also try to lie down as it takes 50% longer to fall asleep in an upright position.

Try to doze for 10 to 20 minutes before the body hits the third stage of deep sleep. Anyone who wakes from this stage often feels groggy rather than refreshed. Set an alarm on your phone.

And if your bosses still aren’t happy, then you can now tell them that it’s all in your genes.

Earlier this year, researchers at the Massachusetts General Hospital’s Centre discovered 123 regions on the human genome that that regulate sleep. For some people, the desire for 40 winks is truly biological.