All language subtitles for first.civilizations.s01e04.trade.480p.hdtv.x264.rmteam

For any civilization to succeed,

it must meet the needs
of its people,

to provide them
with the stuff of life.

This requires a system
of exchange

where demand for goods
is met by supply.

In other words, civilization
has always required trade.

But how did trade shape
the course of civilization?

From the very early period,

trade and exchange was
really important.

It's part of the economic and social
glue that stitches people together.

Trade is the elixir.

It's the thing that creates
collaboration and connection.

It's what enables
the society to progress.

That's, in the end,
what sets us apart

and which has
eventually enabled us

to build a civilization
that is so complex.

We didn't always live this way.

For 99% of our time on earth,

humans had no merchants
or traders.

But then... We settled
down, grew food,

worshiped gods, fought
battles, wrote stories,

built cities,
and created markets.

This is the story
of that transition,

steppingstones on the road
to civilization.

It's a story
set across the globe

in the Middle East,
Central America,

Southern Asia...

All of them seabeds
of civilization.

Here, our ancestors
shaped the ideas

by which we still
live our lives.

This is where
the modern world began.

In the mountains of Oman,

archaeologist Jeff Rose has made
a remarkable discovery...

An ancient rock painting,

a petroglyph,
over 4,000 years old...

50 feet up a canyon wall.

So here it is, the Tanuf mural.

I've seen rock art all up
and down these canyons,

and so I didn't really
think that much of it,

except that when I looked
at it up close,

I saw that there's
actually this motif

which I'd never seen before
in any other rock art in Oman.

So you have this figure here,
and he's grasping these...

These two opposed bulls like this,
and he's surrounded by animals.

But then, when you look
at the bulls themselves,

they've got humps, so these
are... these are zebu cows

from thousands
of miles to the east,

and it makes you wonder
what the heck is going on here.

The zebu is a type of cow found

not on the Arabian peninsula,
but in Southern Asia

on the Indian subcontinent.

Why would their image be
on a rock wall in Oman,

a thousand miles away?

Was it carved
by people from India?

Close to the canyon
are the remains

of an ancient burial site

with more evidence
of foreign contact.

This is called a beehive tomb.

I'm standing here right at
the mouth of the canyon,

so for all we know, those
petroglyphs could be telling us

the story of the guy or girl
buried here in this tomb.

Beehive tombs
are common in Oman,

but archaeologists
have found pottery here

that's not local.

Again, the origin seems to be
from across the Indian ocean.

When we add it all up together,
it looks like we've got

the fingerprint of
a foreign culture

from the Indian subcontinent.

How did these objects
from Southern Asia

end up in this remote,
mountainous region?

In a word, trade.

Well, the first metal that's
used on any industrial scale

in the ancient world
is copper...

And these mountains here
are loaded with copper.

Copper was one
of the first commodities

to be exchanged
in large quantities,

traded over hundreds of miles.

It fueled the rise
of civilization.

Today, copper is still one of the most
important commodities in the world.

Each year,
over $90 billion worth

is bought and sold through
a global trade network

centered on the London
metal exchange.

Business strategist
and author Rachel Botsman

believes trade was vital
to the birth of civilization.

Since humans existed,
we have traded.

It's a necessity,
but it was pretty basic.

It was local, it was
with people that they knew,

so I might exchange a metal pot

for my neighbor's animal skins;

you might exchange
some food for a weapon.

And then what happened
over time is

that trade became more
and more sophisticated

in terms of the goods
that people were trading,

but also the distances
that they were trading over.

We transitioned
from local trade...

Trade with people that we knew,
trade with people that we trusted...

To trusting strangers.

It was a revolution

when we started to trade
long distances.

The ancient copper
from Oman ended up

beside one of Asia's great rivers...
The Indus.

It's the river after which
India is named.

But today, most of its water
flows through Pakistan.

People have been living
alongside the Indus

for thousands of years...

Although it's only now

archaeologists are understanding
the sophistication

of the ancient civilization
once here.

Built 4,500 years ago,
this was a great city...

Mohenjo-daro.

The site,
in a very rough estimate,

is 250 hectares,
which is over 600 acres.

It would be about 40,000 people.

Some estimates also go
as high as 60,000.

Mohenjo-daro was at
the center of a civilization

in the Indus valley
that was as old as any

in Egypt or Mesopotamia.

It was the first
civilization in Asia.

Archaeologist
Uzma Rizvi believes

the Indus civilization
was built on trade,

more so than any other
first civilization.

What the Indus did
really, really well was

really get in on what it was
that people wanted, right?

So what does an elite want?

Everyone wants the beautiful
carnelian beads

that are etched and are
just gorgeous to look at.

They did a fantastic job
cornering that market,

and they also did
a fantastic job knowing exactly

where the resources were,
the best resources.

They're not using
mediocre material.

It's almost like having a brand,

you know, like in
the contemporary sense.

One of the key finds we have
is the figurine.

It's a small figurine, but it is quite
beautiful when you look at it close up.

It seems like a seated figure

with sort of almond-shaped eyes.

You have a band across the top,

beautifully manicured
hair and beard.

The lines are quite pristine.

The carving is actually
quite exquisite.

Exemplary craft,
exemplary raw material,

and exemplary trade networks that really
allow for these cities to blossom.

The city is so vast that much
still lies unexcavated...

But archaeologists have
uncovered large areas

dedicated to the manufacture
of specialist crafts,

such as the smelting of copper.

So every one of these black,
sort of gray-black stones

that you're seeing here, is
actually the waste material

from a secondary
smelting process.

So you can tell just
by the density

of what we're seeing here that
this was a very active place

for production of metals,
of copper, of bronze.

We can actually isolate
the various isotopes,

and so we know, then, the lead isotope
signature from different regions,

and we can say, "oh, a certain amount
of copper is coming from Rajasthan",

a certain amount of copper is
coming from Oman."

There is a very clear sense
that exchange is happening,

and things that are being made in
these kinds of production centers

are being used
in that wider network.

One of the things
made at Mohenjo-daro

is this statuette
crafted from bronze,

produced by combining
copper and tin.

It's 4,500 years old.

A woman with immense beauty

and poise and posture,
and she's standing there

and she's just like,
"here I am."

She has her bangles,

and there is a certain kind
of pride to her.

And you can see it's been crafted
with that same kind of perfection.

That craftsmanship is something
that is unique to the Indus.

How did the people
of the Indus valley

achieve such expertise
so long ago?

Pa.

The discovery of
a small, corroded amulet

may provide an answer.

In France, physicist Mathieu
Thoury is examining the amulet

at the synchrotron particle
accelerator near Paris.

Using a process known as
photoluminescence spectroscopy,

he can work out how it was made.

The amulet is
25 millimeters wide,

so we are working
with a microscope,

which resolution, the smallest
object that you can see,

is a fraction of micron,

and a micron is
a fraction of an hair.

A powerful beam is
projected at the amulet.

Its electrons emit
their own light in response,

allowing Thoury to analyze
those parts of the amulet

hidden by corrosion.

I knew that considering
this pattern was invisible

and extremely organized, it was
very interesting information.

The microscopic
analysis reveals the amulet is

the oldest evidence in the world

of a technique known
as lost-wax casting.

Specialist metal workers use
the same technique today

for doing precision work.

Archaeologist Benoit Mille
is an expert

in its ancient history.

Lost-wax casting allows us to
make very complex objects.

The first part of the process is

to create the object
you want to cast

out of malleable wax.

This makes it possible to produce
a new type of metal object,

made by smelting and casting,
with great precision;

little objects which have
delicate details,

as well as very complex
and varied forms.

Once the wax model is finished,

it's encased in Clay
to make a mold.

This is then heated
to melt the wax away,

leaving an empty mold, which is
filled with molten metal.

This is why it's called
lost-wax casting.

During the Indus civilization,

these craft skills became
highly developed.

You need to master a number
of different techniques.

You need to know how
to make an oven,

and then how to work
with the cast.

To handle metals
at 1,000 degrees is

something quite dangerous,

which you wouldn't
entrust to a novice.

This research shows

there was an extraordinary
ingenuity back then,

that these societies were
amazingly innovative

in terms of craftsmanship.

This technical skill was

behind the growth of trade
in the Indus valley.

Artisans made ornaments,
merchants traded them,

and everyone prospered.

The benefits of trade,
they start with us.

They start with the individual, so
the first thing that they do is

they expand our needs and wants.

They expand the choices
available to us,

but then magic things
start to happen

because for trade to happen,
markets have to grow,

new alliances have to form,
ideas have to...

And people have to bump
into one another.

So trade is the elixir.

It's the thing that creates
collaboration and connections.

It's what enables ideas
to move forward.

I think it's what enables
the society to progress.

But what was so
special about the Indus valley

that allowed a trade network,
and then a civilization,

to start here,
rather than elsewhere?

Ultimately, any civilization
depends on its farmers

to produce enough food
to feed its people.

One of the most recent sites
to be excavated

is on the Indian side
of the valley.

It's a small, rural settlement
called Lohari Ragho.

Archaeologist Cameron Petrie

believes early farmers here
got a helping hand

from the climate.

The Indus civilization is
at the very eastern edge

of the rains that affect the
Mediterranean and the Middle East.

But it's also at the western edge
of the Indian summer monsoon,

so where the Indus
populations live is

directly where these two
weather systems overlap.

This made
the Indus valley unique.

It benefited from two
rainy seasons...

Winter and summer... Which
enabled its farmers

to grow more than one set
of crops each year.

Its beneficial location gave
the Indus valley

an advantage over all other
first civilizations.

In Mesopotamia and Egypt,

they harvested wheat, barley,
sorghum, and millet.

In Mesoamerica,
it was squash and corn.

But nowhere was farming
as productive

as the Indus valley.

So what that means is that they
could be much more adaptable

to their situations.

They're able
to maximize the output

from the hinterlands
around their sites.

It does create, in some ways,
a sort of economic drive

for the local economies
to have a surplus

and be relatively well-off,

and therefore to engage
in things like trade.

And in some ways,
it's part of the economic

and social glue that
stitches people together.

We've got a nice, interesting
dynamic with the Indus,

so it's simultaneously
different... people are varied

and they're probably speaking
different sorts of languages...

But there's things that stick them
together, and it's the access

to this trade network and the economic
products that they can obtain.

Today we're in luck. So the
team's been excavating carefully,

and we've found
a nice carnelian bead.

What's interesting is that it's
probably coming from somewhere

down in Gujarat, 800 kilometers
as the crow flies.

But it does give us
a nice, neat example of...

Or a demonstration of how
this trading system operates

and the sorts of things
that are moving around.

The Indus valley
was previously thought to be

a predominantly urban
civilization.

But now, archaeologists
are discovering

that alongside the cities,
there were thousands

of smaller sites, joined
up in a nexus of trade.

Here, the agents of civilization

were not soldiers,
bureaucrats, or priests,

but traveling merchants

who would establish
new trade routes

to buy and sell their wares.

Cotton provided a lucrative
raw material for merchants,

who would barter for it by
offering other goods in exchange.

As a result, settlements emerged
to service this new trade.

Archaeologists
Adam and Lily green

are using ancient maps
and local knowledge

to establish the full extent of
the Indus valley civilization.

So what I think we have here at this
stage is a small-scale settlement.

We're picking up lots
of evidence of activity,

evidence of building up
the site,

living day-to-day...
Everyday-life kind of things.

So if you kind of walk
along here,

you'll see an occasional
piece of broken pottery

that's been plowed over
and over and over again

by tractors as they're preparing
the soil for these cotton crops.

You can see this.
This is really great.

Have this black-painted
body shard.

This is a piece of a vessel
with black paint on it.

All these groups were engaging in
different forms of specialization,

creating a range of goods

that were being fed into
the system as a whole.

So there had to have been large-scale,
long-distance systems of contact

and interaction that tied
the whole civilization together.

For trade to flourish,

there needs to be
a set of rules,

a protocol for exchange
between strangers

hundreds or thousands
of miles apart.

This was true in ancient times
just as much as today.

You'd ask many people how does trade work,
they would say, "well, it's money."

Money is a currency
of transactions,

but for human beings to interact,
for human beings to trade,

the social glue, the lubricant
that makes this work, is trust.

That's the most fragile
and precious asset

that exists in any form
of trade network.

When you trade with a stranger,

you don't know the outcome.

This is what I describe
as a trust leap...

And the easiest way to think
of a trust leap is

it's when we take a risk
to do something new

or to do it differently from
the way we've done it before...

And therefore, the currency
that makes it work is trust.

If there is no trust,
you cannot trade.

But how do you decide
if you can trust someone?

Is it based
on their appearance...

The way they look you
in the eye...

Or their body language?

Psychologist Tim Hahn

believes trust is so fundamental
to human interaction

that our brains have evolved
to be innately trusting.

To test this, he is running
an experimental trust game

in which two strangers are
paired through a computer link.

Each is given a pot
of money to trade with.

Hahn records
their brain activity

during every stage of the game.

You're actually measuring

how your brain responds
to the stimuli in the trust game

by looking at the brain waves.

How much money do you want
to give to player two?

Whatever amount
player one decides to give

to player two will be tripled.

Trust, in the case
of our experiment, is

always entrusting money
to another person in the hope

that this person will return some
of your money back to you...

And even more, hopefully,

than you've initially
entrusted to that person.

Player one has given you 45.

How much money
do you want to give back?

Whatever amount
player two decides to return

will also be tripled.

The game is designed so that
the more you trust a stranger,

the more you are rewarded.

It's a win-win scenario,
mirroring the process of trade.

If that works well over
the course of several rounds

of the trust game,
both players can learn

that they can trust each other,
and then they start to invest

more and more money
into the other person.

More and more money
is flowing back,

which benefits both parties.

Hahn's research reveals that
the most crucial moment occurs

at the very start of the game,

when the two strangers meet
for the first time

and they have to overcome
their initial caution.

The thing that we've shown
in our experiment is

that even before you start
to know a partner,

you will display
some level of trust,

which means that over time,
pretty much any relationship

where trust
is answered with trust

will evolve into a more
trusting relationship.

We as humans are probably
very well-equipped to trade

because we all show at least
the basic level of trust.

And that seems to be, if not
hard-wired into our brains,

then still implement in our
brains in such a smart way

that we will always trust,
but that we're flexible

in responding
to different circumstances

and different partners
in trade interactions.

That's, in the end,
what sets us apart

and which has
eventually enabled us

to build a civilization
that is so complex.

Congratulations,
player one. You have won 240.

Congratulations, player two.
You have won 180.

To enshrine trust
between buyer and seller,

the merchants
of the Indus valley

pioneered their own method
of doing business.

The people of the Indus
valley were among the first

to realize the full
potential of trade.

They found many innovative ways to facilitate
the exchange of goods between merchants,

and perhaps the most inventive
way was using seals.

Many of these seals have
tally marks...

You know, 1, 2, 3, 4,
up to 7 tally marks...

Followed by symbols,
such as a stalk of wheat

or a stalk of barley,
which seems to indicate

that something is being counted,
perhaps a quantity of grain.

And there's other symbols
that could potentially stand

for weights and volume,

and perhaps symbols that stand for
the names of merchants' locations...

Or even state institutions
such as, you know,

the tax department
or the customs department.

These Indus seals could also have
been used as an ancient barcode,

so numerous Clay tags have been found
in different sites of the civilization.

The information that
these Clay tags might contain

include the source and the
destination of the goods.

Some of these seals and the tags
associated with them

have been found snapped,
almost deliberately snapped.

These snapped seals or tags could
denote the fact that a transaction,

a business transaction, has ended
or concluded, and that's been done

to prevent future abuse of the
legitimate authority of the seals.

Each seal featured
a different animal,

which may have been used
to identify individual traders,

like a modern-day logo.

Thousands of years
before Coca-Cola and Nike,

the people of the Indus valley
discovered the power of branding.

It's something that even an
illiterate person can just glance at

and understand the power
of that particular image...

Ancient brands of
the quality of the goods

or the affiliation
of the merchant

to a particular clan
or community.

The same attention to detail went
into the planning of their cities.

Everything was designed to
promote the free flow of trade.

In any civilization,
happy, well-ordered people

are more efficient people
with more time for business.

What is distinct
about the Indus, as compared

to many other sites
from 5,000 years ago

around the world is that we
don't have the ziggurat.

We don't have
the monumental palaces, right?

We don't have the large temples
with the columns.

But what we do have is
an incredible monumentality

of organization and planning,
of standardization.

There is a monumentality
of thought here

that goes beyond what we generally
see at this time period.

The Indus, in my mind, was
actually far ahead of the curve.

It's not kind of
an organic formation

responding to each other, seeing
how the population grows.

This city in particular is just
planned from top to bottom.

You can walk through the city
and you can feel it.

It feels like a modern city.

All the architects and those who were planning
this place were very clear in their mind.

They knew what the city needed in order
for it to be a successful city...

Like thinking environmentally, like thinking
about where is the wind flowing from,

so you may not have an air conditioner, but
you have really fantastic wind tunnels.

So you can stand here in
a little bit of shade,

and you actually get
a great breeze coming by.

Fresh water and a sewage system

are often thought to have been
invented during the heyday of Rome,

but the people of
the Indus valley got there

2,000 years before the Romans.

Here we have a great example
of a second-floor bathroom,

and there was a terracotta pipe
that was placed inside

for drainage, covered entirely,
right... we can see it

because it's been excavated... and
then coming down the chute here.

And along both sides
of the street, we have drainage.

So it's coming straight in
and moving out,

out of the city, which is
just really fantastic.

My students always
laugh about this.

They're like, "yes, the one thing we learned
about Mohenjo-daro is the drainage."

We know there's drainage."
But it is remarkable drainage.

It is not just drainage.
It is fantastic drainage.

Every single house has been
thought through.

This is planned.
This is orchestrated.

This is a lot of control
and a lot of thought.

This is really what
makes Mohenjo-daro,

and the Indus
in general, remarkable.

These individuals knew
what they were doing.

This is better-organized than many
other cities I've lived in today.

At the Southern end
of the Indus valley region,

there was another important
trading city, Dholavira.

The coastal lowlands of northern
Gujarat were a wilderness

compared to the rich farmland
further north.

Today, the area has been
abandoned to nature...

But the people of the Indus

were able to make this a home.

Archaeologist Michel Danino

has made a lifelong study
of Dholavira.

It's a very arid region,
not very hospitable.

For the city to be sustainable,

they had to store rainwater.

Dholavira is ringed
by a series of reservoirs

that stored the monsoon
rainwater each year.

It is the oldest system
of urban water management

anywhere in the world.

We are here at the bottom
of the eastern reservoir.

Its length was about 73 meters.

That's nearly one and a half
Olympic swimming pools,

so therefore, this would have
been a very impressive sight,

especially whenever it was full.

It has been estimated

the city's reservoirs could hold
79 million gallons of water,

enough for 14 gallons
per person per day.

This part of Gujarat is
an earthquake zone,

but the reservoirs seem
to have been designed

to withstand seismic activity.

You can see those...
What looks like vertical lines.

Actually, they're simply
lines where the... I mean,

the stones are not joined,
they are not overlapping.

In civil engineering,
this is called a fuse;

in other words, this is
the weakest part of the wall,

and if there is,
for example, an earthquake,

if the whole wall is
interlocked,

perhaps a big portion of it
might just fall out,

whereas, if you keep
a weaker portion here,

perhaps only this...
Or a little bit on the sides,

or maybe only one of
the sides... will fall out.

So if this is an earthquake
safety measure,

then it was really
well ahead of its time.

Wherever Danino looks,

he finds the same evidence
of an engineering mindset

among the ruins;

the streets, the buildings,
even the bricks,

were all made to measure.

The bricks were
standardized in the sense

that the width is twice
as much as the height,

and the length is
twice as much as the width,

so it's 1:2:4.

This was actually
a stroke of genius

because it gives you
the maximum structural strength

with a minimum amount
of building material.

Mathematical
principles were applied

to all the cities of
the Indus valley.

Construction was always based
on precise, rising ratios,

where the length of a building
was larger than its width.

This served
no practical purpose;

it made the building work
more complicated,

but it suggests a faith
in a core idea...

The power of progress.

This faith underpinned the principles
of a trading civilization.

There's a very clear concept that
it is something which has value.

In later Indian traditions,
this concept of growth is going

to be very,
very clearly expressed

in the building of altars,

in the building of temples
and so on,

invoking a desire
for prosperity,

for auspiciousness.

And they would have seen
this ratio as...

Certainly as auspicious,
if not, perhaps, as sacred.

When trying to understand
the first civilizations,

archaeologists look
for evidence of the forces

that might bind people
together...

Perhaps a king or an emperor
who lays down the law

and imposes order.

But in the Indus valley,

no such evidence has been found.

Archaeologists also look
for temples,

the existence
of organized religion

with a unifying system
of belief.

Again, here in the Indus valley,
none has been found.

Another
recurring feature is war...

As the weak are weeded out
and the strong prevail.

But for the people of the Indus,

it was a different story.

With trade came peace, giving
civilization here a different flavor.

It functioned like
a modern business corporation,

designed to maximize
its own wealth,

not by ruling with
an iron first,

but by creating a loose web
of like-minded interests...

Franchise holders up
and down the valley

who share the same desire
for trade and prosperity.

In days when the fastest
communication is a boat,

river boat, or a bull and cart,

and you have cities
2,000 kilometers apart,

it doesn't make sense to run
this as a centralized empire.

There were original chieftains

which were controlling their regions,
but they were working together.

It's very clear that you
have one mind at work.

Often trade is looked through
in terms of economic benefits,

but if you look back in history
and you look at trade patterns,

typically, countries
that trade with one another

do not go to war
with one another.

There is a human
understanding there.

It creates civilization.

It's what enables
a civilized society.

The ideas seeded
in the Indus valley

are the very essence of
our own economic system...

The link between trade,
wealth, cities, production,

consumption, civilization...

Ideas we may think are modern,

but were actually road-tested
4,500 years ago.

Instead of priests, today
there are traders;

instead of pyramids and temples,

there are the high-rises of
the central business district...

Monuments to a trust
in prosperity.

Trust and trade, they work

in this beautiful feedback loop.

For trade to start in any
civilization, you need trust,

and then the more trade you have, the more
trust you have, and so the loop continues,

and the benefits are
really exponential.

In high-trust societies, they
don't just thrive economically;

you actually see individuals
in society thrive

because they have more freedoms,
they have more empowerment.

You see more entrepreneurship,
you see more human empathy.

At the height of its expansion,

the Indus valley civilization
covered an area

over half a million
square miles.

But its trade links
reached even further:

In the north and east,

to modern-day China
and Afghanistan;

in the west, as far
as the Persian Gulf.

This was a civilization that
produced beautiful artifacts.

Its people were well-fed.

Its cities were clean.

Inequality was low,
and it was peaceful.

What could possibly go wrong?

Around 1900 BC, the seals... so the
all-important seals that were crucial

to the success of the Indus
civilization and the Indus merchants...

Disappear from
the archaeological record.

It's almost as if something
catastrophic has happened

to disrupt trade and, indeed,
the Indus civilization.

All of a sudden,
if you don't get a surplus

one year, you can probably
compensate for it.

If you don't get a surplus
for a second year,

you might be able to compensate
for it, but if it keeps going on

and on and on, then the economy
sort of has to change.

And I suspect that would have
resulted in a social instability.

Maybe the city starts to come under
strain in this social strife,

and the urban fabric
starts to break down.

More and more,
the thinking towards climatic,

environmental changes.

A big drought that
struck 2200 BC,

and the drying up of
the Saraswati river

in the eastern region
of this civilization.

One of the most
striking things to me

is that somehow
that ability to control

and organize large landscapes
has crumbled.

There's a shift
in belief patterns,

and that shift alters
the ways in which people live,

and that's when you begin to see
all of this break down.

The collapse of any civilization

is never a simple story.

How did the world
of the Indus people implode?

When its cities were
first excavated,

skeletons were found
among the ruins.

They were dated to the final
phase of the civilization.

Some were buried in cemeteries.

Others appeared to have died
where they fell.

Bioarchaeologist Gwen Schug

has found a clue
to what happened

by studying
one particular specimen.

This skeleton was
the first individual

that we discovered to have leprosy
from the Indus civilization,

and the presence
of leprosy in south Asia

at that time
was previously unknown.

It was the oldest evidence
of leprosy in the world

by about 1,400 years.

We find evidence
for mycobacterial infection,

leprosy, and possibly
also tuberculosis.

This was the downside
of long-distance trade.

It opened a door
for new pathogens

to enter the human population...

Infectious diseases,
spread by close contact...

The price of civilization.

The bones also reveal

the diet of the Indus people
collapsed at this time.

We start to see evidence
for vitamin-c deficiency.

Their basic nutritional
requirements couldn't be met.

The fact that this is also
present in very young infants,

right around the time of birth,

demonstrates that pregnant women
were not able

to get their basic needs met
for food.

All of the foodstuffs
and different products

that were coming in
and out of the city,

it's not happening anymore.

Trade brought disease.

Disease disrupted
the supply of food.

That led to a breakdown
in social order.

This is how civilization falls.

We find that the prevalence
of interpersonal violence climbs

within the skeletal material
that's available,

to about 50% of the individuals.

A large number of
the crania are impacted

by traumatic injuries.

It sort of paints a picture

of the experience
of that loss of social control.

What's fascinating is you
can look back over history

and look at the collapse of civilizations,
and they follow this similar pattern.

Most recently, we've seen this

in the financial crash,
in that you have a system

that people have confidence in,

and then something goes wrong.

Someone behaves badly,
someone becomes greedy,

and the first thing
to go is the confidence.

And then quickly,
it's like a house of cards.

The weakest link
in any society is us.

Over a 200-year period,

the Indus valley's vast international
trade network fell apart.

As the Indus valley
civilization is collapsing,

there are reverberations
across the entire region.

So here in the ancient kingdom
of northern Oman,

we see a profound social change, and
it's exemplified here at this site.

During the heyday
of the Indus valley,

down there on the coast,
there was a thriving village

openly trading with
their neighbors across the sea.

And as the Indus valley declines,
that settlement moves up

to the top of this mesa,
this natural citadel.

They're hunkering down, and they're
building walls here to protect themselves,

so the trust that was tying the whole
network together is beginning to unravel.

Within a short time,
the world of the Indus people

turned to dust;

trading centers
abandoned, cities ruined,

its legacy forgotten.

Civilizations are,
essentially, social experiments

and large groups of people
living together,

being civil with one another, but there's
a natural ebb and flow to this process.

Inevitably, at some point,
all civilizations rise and fall.

So it's our job to ride out
these social transformations

and build on the best ideas
of our ancestors.

Trade has always been
a trigger of change.

It encourages us
to come together,

to exchange things...
To share ideas...

To create societies built on
cooperation, trust, peace.

This was true for
the first civilizations...

And it's still true today.

Trade...

The driving force
of civilization.

First civilizations
is available on DVD.

To order, visit
shop.PBS.Org

or call 1-800-play-PBS.

Also available for
download on iTunes.