I once had a big garden and a little duckpond on it with wild ducks. Any watching of these animals made me realise how savage nature is. We are animals and we behave similarly but are gradually improving ourselves.
This whole article is intellectual self abuse as were the following comments, have a lovely day.

Meanwhile this reference provides a completely different Illuminated Understanding of the Garden or the Paradise of Indestructible Light
http://www.beezone.com/adidajesus/adamnervoussystemeveflesh.html#trueteachingrenewalculture particularly the first part at the top of the page

This related reference provides a unique Understanding of the true purpose of Creation Myths http://www.beezone.com/da_publications/creamyth.html

And why not also check out one of Ken Wilber's first books, namely Up From Eden A Transpersonal View of Human Evolution and then his extraordinary Sex, Ecology, Spirituality The Spirit of Evolution

So what this article shows that humans are progressing slowly when
looked at in our time bases.
However there once was PAX Romana, then some time later the League of
Nations and the United nations. Imperfect of course but a move in the
right direction.
Just don't be impatient, we will get in right in the next couple of
thousand years.

On this occasion, easy to agree, with Thinkabit.

The evolutionary evidence is clear that, millions of years inside the genome, humans and chimps are uniquely murderous species. "Lethal intergroup violence" is the polite term that the anthropologists use.

Humans also have unique capacities for arrogance and delusion. With population ballooning from 2b to 8b in a century, 50% of the land surface converted, the 6th wave of extinction, all of a sudden United Nations "net zero" is going to save us.

It is a documented fact that humans had wars way before 6000 years ago.

Still, the author has some clue about life becoming relatively worse, more stressful and violent around 6000 years ago, more precisely 5123 years ago when the harsh age we live in, the Kali Yuga, began. Its arrival was prophesised by the sage Markandeya - http://www.sacred-texts.com/hin/m03/m03189.htm

Scripture tells us that life goes through a cycle of 4,320,000 years, divided into four ages, lasting 4*432000, 3*432000, 2*432000 and 1*432000 years respectively. The first, called Krita-Yuga, being the best and most peaceful and balanced while the last, the shortest but worst and most violent, is the Kali-Yuga in which we now live for the last 5123 years - http://en.wikipedia.org/wiki/Kali_Yuga

It follows that while indeed there once was an "Eden", it ended 2,165,123 years ago, not 6000!

At that time, peace, calm and generosity was natural, so there was no need for kings or any other kind of regime to enforce it.

There still is a minor "Eden" available, a particular area in India called the Naimisha Forest, that is immune to the Kali-Yuga - http://enacademic.com/dic.nsf/enwiki/4976913

The human race has been much the same for hundreds of thousands of years and more?
Our strongest characteristic is the will to survive.
The methods used to achieve survival varied with the living conditions at the time.
A change in climate would have initiated a different approach?
(the drift of land masses to different areas was a slow change)
Also rocks falling from the sky.
(ask the dinosaurs about that)

As someone pointed out, we need to remember we are part of the animal kingdom.
We share many of their characteristics.
Observe them, and see yourself.

The one big advantage we have is our leaning towards logic and reason.
As these attributes developed, we found we could learn useful things about our surroundings.
We were able to use that knowledge to plan more effectively.
We have been able, collectively, to achieve some rather remarkable outcomes.
Vehicles trundling around on another planet for one.....

But the warlike instinct we needed for survival is still with us.
The basic skill set needed for survival remains intact.
So, it is almost certain that, long ago, we behaved much the same as we do now.
We are warlike now, and were likely warlike then?

Perhaps our long ago ancestors did squabble less?
But if they did, it was because they lived further apart?
Now we are crowded together, friction and rivalry have more chance to cause unrest?
So population growth is another factor which contributes to having a less peaceful world?
Plot the coordinates, and look at the shape of the graph?

But the instincts to fight and steal were always there.
So I really doubt there was a 'golden age' of peace and tranquility.
But all things are relative, so if we stretch a point.....
Thank you to the writer for provoking 'the many' with his words.