Stone Age Animals Living in a Space Age World

Anatomically modern humans have been around for approximately 200,000 years, with our earlier ancestors stretching back around 2 million years. But it wasn’t until about 2,000 years ago in Rome that the first human city hit 1 million people.

For the majority of human history we’ve been hunter gatherers, living closely with and relying on nature to survive. Approximately 10,000 years ago we started farming. For the first time in human history, we were able to produce food en masse. Stockpiling food meant we had more time to spend on things like art, science and music. This was essentially the birth of civilisation.

Still, in the 1800’s, only 3% of the population lived in urban areas. By 1900 it was almost 14%, and it increased rapidly from there – to 30% by 1950, and 50% by 2008. By 2050 around 70% of the world’s population is projected to be living in an urban area.


There are now nearly 160 cities around the world with populations over 1 million, with some mega-cities like Tokyo hosting a staggering 33 million people with a population density of 4,750 people per square km. To put that into perspective, the population of Tokyo is nearly 50% greater than that of the entire population of Australia.

Even more extreme, Mumbai has about 14.5 million people but nearly 30,000 people per square kilometre. This density is primarily due to the Dharavi Slums, a small area with a crazy 300,000 people per square kilometre. That would be like Manhattan having a population of over 17 million people or the USA having a population of over 2.9 trillion people. That’s a lot, ‘nuff said.

As big as these cities are, in the grand scheme of human history they’re brand new.


Percentage of Human History Before We Discovered Farming


Percentage of Human History Before We Started Living in Large Cities

If the whole of human existence was 1 day, we’ve been living in cities for about 14 minutes.

We are essentially a stone age people living in a space age world, no different physiologically than our hunter gatherer ancestors. Unless you count rampant levels of obesity and chronic illness.

Researchers at the University of California, Santa Barbara demonstrated this physiological similarity clearly when they challenged subjects to spot changes in images. They presented scenes with animals along with images of vehicles and other inanimate objects. Considering most people see cars every day, and cars pose a much greater potential threat to people in every day life than animals do, their research still showed that the priority in Visual Monitoring was biased towards the animals.

While we can all agree it’s a good thing not to have to worry about being eaten by a predator, other aspects of city life aren’t as healthy for us. We’re built to live in nature, not concrete.

Forest Bathing

In 1982, the Japanese Government started a program encouraging people to spend more time in nature, called Shinrin-Yoku. In Japanese shinrin means forest, and yoku refers here to a ‘bathing, showering or basking in’. The idea was that you would walk through the forest, without distraction, taking in all the sights, sounds, and smells. In other words, paying attention to your surroundings, or practicing mindfulness.

To practise Shinrin-Yoku now, there’d be no listening to music, no checking your emails, and no talking on your phone allowed while you go for a walk through the woods.

In 1990 Dr Yoshifumi Miyazaki conducted a small study in the forests of Yakushima. Yakushima is home to cedar trees that are over one thousand years old and is considered one of the most loved forests in Japan. He found that a 40 minute walk in the forest resulted in lower levels of the stress hormone cortisol compared to a 40 minute walk on a treadmill in a lab. So it’s not just the walking that helps, it’s also something about the natural setting.

Since then many other research teams have decided to objectively measure physiological markers while subjects spent time in nature. The results of nearly a dozen studies conducted with over a thousand subjects across 24 forests came to the same conclusion: being in nature makes a difference.

Time spent in nature resulted in measurable results like lower cortisol, blood pressure, and pulse rate, along with subjective results like reduced psychological stress, depressive symptoms, and hostility. Subjects also reported improved sleep quality and a feeling of being more alive. Researchers Frances E. Kuo and Andrea Faber Taylor even found that being outside in nature reduces ADHD symptoms in children.


Your Brain in Nature

While viewing scenes of urban settings, volunteers in a Korean MRI research study by Gwang-Won Kim and colleagues showed more blood flow in the amygdala, which processes fear and anxiety. While viewing natural scenes, the MRI showed more activity in the anterior cingulate and the insula—areas associated with empathy and altruism.

In another study, after scanning the brains of 38 volunteers before and after a 90 minute walk in either a large park or a busy street, Stanford researcher Greg Bratman and his colleagues showed that the nature walkers, but not the city walkers, showed decreased activity in the sugenual prefrontal cortex—a part of the brain tied to depressive thinking.

Spending extended time in nature also helps your brain rest, according to David Strayer, a cognitive psychologist at the University of Utah. His research has shown that being in nature allows your brain to enter more of a flow state, so it can rest and be more present. His EEG measurements have shown less energy coming from midline frontal theta waves—a measure of conceptual thinking and sustained attention.

Exercise Outdoors

The gymnasium, athletic track, and the swimming pool are ameliorators to our synthetic modern living but they are not the same as the rocks, rivers and trees. The Greeks knew that the sea was for the swimmer and the earth for the feet of the runner—Professor Peter J. Arnold

If just looking at pictures of nature can have measurable effects on us, what about exercising in nature? Professor Jules Pretty and colleagues, as well as other studies, have found a synergistic benefit to ‘green exercise,’ or exercising while being exposed to nature, beyond the benefits of exercise alone.

One research study demonstrated that children who go outside to play have a 250% increase in physical activity compared to kids who spent time playing indoors. With childhood obesity at epidemic levels, can we really afford not to be sending our kids outside to play? But what’s also interesting is that among a large group of healthy 5-year-olds, those who are the most aerobically fit also have the highest attention scores, and those who have the best balance also have the most efficient working memories.

As for adults, in a study published in Medicine and Science in Sports and Exercise in 2011, research subjects walked on either an indoor treadmill or an outdoor track at their own pace. The results showed that the outdoor walkers chose a faster pace, had more positive thoughts, and perceived less overall exertion than the indoor walkers.

It shouldn’t come as any great surprise that as a society we need to spend more time outdoors, but it’s always good to get a reminder from time to time. With all the physical and mental benefits of nature, getting outside in a natural setting should be a priority for both children and adults.