[music]

>>[Narrator: Desmond Morris] Of over a million 
species of animals on our planet, one species has

come to dominate all other lifeforms, and 
to alter dramatically the face of the Earth.

It's a species that if we remove its protective layer 
of clothing, reveals a rather strange anatomy.

A species I once referred 
to as "the naked ape."

Physically the human being is a puny primate with a 
vulnerable, unprotected skin, with no natural weapon.

No armor, no sharp spines, 
no venom, no fangs or claws.

Yet equipped with little more 
than an enlarged brain,

this compulsively curious creature has 
come to dominate the natural world.

What is the secret of its 
lavish, unprecedented success?

[music]

Anatomically, the human animal is unusual, to say 
the least. Its lack of hair is unique among primates.

Contrasting with other apes, its face has a protruding nose, 
whites to the eyes, and lips that are turned inside out.

Its legs are long and straight. And unlike 
any other mammal, it walks bipedally.

The breasts of the female remain swollen throughout 
her adult life, even when they're not giving milk.

Again, a unique feature.

There are a few surviving patches of hair, including on the 
tops of the heads, in the armpits and around the genitals.

The male has the largest 
penis of any primate.

And the human animal is the only primate 
that possesses rounded, fleshy buttocks.

Altogether, these unique features 
make us a very strange ape indeed.

And for a student of animal behavior, even more 
peculiar than its anatomy are its activity in the wild.

I'm a zoologist and since man is an animal, I can see 
no reason why my work, and also in this series,

I shouldn't study this particular species in the same 
way that I've studied many other animals in the past.

The secret is patient observation.

For me, the ideal method is to go out into the field 
and study humans in their natural environment.

In the streets and parks, the shops 
and offices, the villages and cities,

to analyze their natural behavior as it happens 
in real life situations all over the world.

Everywhere I go, I'm struck by how similar all human 
beings are to one another in all important respects.

Of course, there are many superficial 
differences and these are often so impressive

that we pay too much attention to them and start 
treating one another as if we belong to different species,

with disastrous results. But, despite all our 
variations in costume, ritual and believe,

biologically we're all astonishingly close to 
one another. A fact which I find very reassuring.

Back in the late 1960's, I was sitting in 
this very restaurant, on the island of Malta,

talking to my publisher. I drew his attention 
to the fact that on the other side of the road

there were two men gesturing 
in a particular way.

The way they were holding their palms 
to one side was fascinating to me.

And he said, "You know, you look at people 
the way birdwatchers look at birds."

And I said, "Yeah, I suppose you could call 
me a 'man-watcher.'" As soon as I'd said it,

it was as if I'd fired a starting 
gun on a major, new project.

One that was to engross me for many years to 
come and take me to over 60 different countries.

It was wildly ambitious, but I decided to make 
a complete classification of all human actions,

gestures, postures, expressions all over the world. 
And this was going to take a very long time.

I was going to do for actions what 
dictionary makers had done for words.

I began making huge charts naming every facial 
expression, every gesture, every movement, every posture.

I kept at it for month after month. And 8 years later 
I had completed the work and was able at last

to introduce people to the fascinating 
subject of human body language.

One of the first problems I encountered was 
that even the simplest human action,

such as the handshake, 
has countless variations.

Sometimes it's reduced to a mere palm touch, 
as with these Maasai elders in East Africa.

But, in other countries it 
becomes more elaborate.

In Mali in West Africa the hand-shaker briefly 
touches his own forearm as the palms clasp.

In Morocco, the hand-shakers kiss one another's 
hands at the same time as clasping them.

And in Turkey, these Kurdish farmers have taken 
a simple action and converted it into what

amounts to a minor ritual. It's the local rule that they 
can't start bargaining until they are shaking hands.

And they have to keep on doing 
so until the deal is struck.

The essential feature of hand-shaking 
is that it's an egalitarian act.

Regardless of their social standing, the two people 
involved are momentarily performing identical actions.

This meeting as equals that has spread 
around the world is comparatively recent.

In earlier times when greeting, it was common 
for the less important individuals to literally

lower themselves as a sign of respect. In some remote 
parts of the world we can still see this even today.

The Toda people of South India 
still perform this body-lowering ritual

with high-status feet 
placed on low-status heads.

Despite their variations, all these 
greetings have one thing in common.

They're all fine-tuned to the precise 
context in which they occur.

So many gestures have different 
meanings in different places.

You have to be quite careful how you use your hands 
when you're in a marketplace in a foreign country.

Now to me, this means everything's fine or O.K. 
But, if I happen to be in the south of France

it would have a different meaning. There the ring 
shape made by the hand symbolizes a not or a zero.

So, in south of France this 
means zero or worthless.

So, you don't want to say the 
wine was "great" [gestures]

because in fact you'd be 
saying the wine was worthless.

It gets even worse if you go to Sardinia 
because there the same gesture is an obscenity

with the ring shape symbolizing an orifice. 
And if you think you're going to say

something is great in Sardinia like this, 
believe me you'll be in trouble.

There's another way you can make mistakes 
with gestures as you move from place to place.

Because a single message is given in 
a different way in different countries.

The crazy sign. How do you say to somebody 
"you're crazy?" Well, here in Rome you do this.

But, in England I would probably do this, the 
temple screw, saying he's got a screw lose.

Or I might say his brain is 
going round and round.

Or I might tap my head saying "what's 
he think he's got inside his skull."

In some countries you do it with two hands. 
It varies from place to place.

If you go to Japan you have to be careful because 
if you it this way it means he's intelligent.

You have to it in the counter-clockwise direction in 
Japan if you want to say that somebody is crazy.

So, all over the world, the same message 
is given in a slightly different way.

One of the most obvious examples of this and 
one of the most dangerous is the insult gesture.

This Turkish pedestrian displays his 
anger with the trust of a stiff forearm,

using his arm symbolically 
as an aggressively erect penis.

A slightly more obscure insult is the cornuto, 
or horn sign, frequently seen in Italy.

It implies that that victim of the insult is 
a cuckold, that his wife is unfaithful to him.

In North America, the most common 
insult is the middle fingered jerk,

employing the middle finger 
as a symbolic penis.

This is an ancient Roman gesture and 
is well-known in many countries.

Much more localized 
is the Greek moutza.

This dates back to Byzantine times and symbolizes 
excrement being pushed into the victim's face.

In Britain the main insult is a two-fingered gesture 
which dates back to the battle of Agincourt.

It's a gesture that foreigners sometimes 
confuse with the "V for victory" sign,

but that's performed with the 
hand the other way around.

Most regional body language has a long and
complicated history, with the origins often forgotten.

One of the special qualities of regional 
gestures is that they are amazingly conservative.

They remain confined to their own particular 
area regardless of the fact that all around them

national boundaries keep changing. As a result 
of this, within a particular country today you

can find what we can call a "gesture frontier." A place 
where one gesture stops and another one begins.

This is a gesture frontier behind me. 
It's the Massacre Range in Central Italy.

And south of here in Naples people use, for 
example, the head toss when they're saying no.

Up in the north in Rome they shake their heads 
from side to side when they're saying no.

And we were amazed to find that here, the Massacre 
Range is a very narrow area, just a few miles,

where you get the switch from 
head tossing to head shaking.

The explanation of this switch is astonishing. 
In origin, the head toss is a Greek gesture and

many centuries ago the ancient Greeks colonized 
southern Italy and started to move north.

And it was here at the Massacre Range that 
they stopped their advance 2,500 years ago.

And to this day, in the north people still give 
the typical European head shake when saying no.

While in the south they still give 
they ancient Greek head toss.

And this difference has survived despite 
all the mobility of modern life

and the spread of films and television 
programs. The old gesture frontier remains.

Yes signals made with the head are 
just as complicated as no signals.

In most parts of the world people nod 
their head up and down when saying yes.

Many people mistakenly assume that this action 
is completely global, but this isn't the case.

There are two areas where 
something else happens.

One of them is India, where instead of being nodded, 
the head is wobbled side to side when saying yes.

To visitors this looks like a maybe, but 
it's not. It's a sign of definite agreement.

When your taxi driver agrees with you, you 
can see his head rolling from side to side.

You get the impression that he's undecided. 
But, every wobble he makes means yes.

In another region, it's not just 
the visitors who are confused.

Even the inhabitants are not 
always sure what's going on.

Here in Bulgaria they use both the head 
nod and the head wobble when saying yes.

This creates total confusion. Why on Earth 
they do this remains a mystery, even to them.

Although gestures often persist for hundreds or even 
thousands of years, sometimes they may change

their meaning as they're passed on 
from generation to generation.

We all think we know what the popular 
thumbs up and thumbs down gestures mean.

[children shouting boo or yay]

If we go to the cinema we are left in little 
doubt as to the significance of these gestures.

The thumbs up for good and the thumbs down 
for bad are very well known gestures.

And many people can tell you how they began. 
It was here in the Colosseum in Rome.

If a gladiator at the end of a fight was to 
be spared the crowd gave him a thumbs up sign.

If he was to be slain it was a thumbs down sign. 
That's the popular story, there's just one catch.

It's completely false. 
It never happened like that.

In ancient times if the gladiator was to 
be spared they gave him a covered up thumb,

the "pollice compresso." This means 
the compressed or squashed thumb.

If he was to be slain then they mimed the 
act of stabbing him with a sword like this.

Because they were high up they 
stabbed downwards like that.

That's the truth of the matter and 
the next time you go to the movies,

if you happen to see the thumbs up you'll 
just have to take it with a pinch of salt.

It's almost certain that our ancestors used 
gestures to communicate specific information

long before they had a spoken language. Even 
today with words as our main form of communication,

there are still situations where 
gestures have a definite advantage.

For example, they can communicate information 
over a far greater distance than would be

possible by shouting. At race tracks in England, the 
white-gloved tic-tac men signal changes in the

betting odds to the bookies so that they can keep up 
with the alterations the arrivals may be making.

The flashing movements of the white gloves can 
be seen even at night and at a great distance.

In some sports a gestural sign language not 
only conveys information over a great distance,

but also allows messages 
to be kept secret.

The coach of an American football team 
transmits complex signals to his quarterback

using coded hand signals that conceal 
his intentions from the opposing team.

Even if the opposing team does manage to 
crack the gestural code at any one time,

it's being constantly 
changed to confuse them.

On the floor of the Bombay stock exchange 
hand gestures provide a powerful tool

when competing for attention. The frantic sell and 
buy signals, indicated by the position of the hands,

can be the basis of huge deals.

An insistent flick of the fingers the only way 
to attract attention above the roar of the crowd.

In the eerie silence of the Australian Outback, 
these two Warlpiri women are conversing quite

adequately by gestures alone. Now they're not 
deaf and they're perfectly capable of speech,

but local custom demands that as an act of 
mourning they don't utter a word for months

after a tribesman has died. It's 
their version of wearing black.

Clearly gestures are important to us, but why 
are we so much better at signalling with our

hands than other animals? The answer of course 
is that we are the only mammals that are bipedal.

They are all quadrupedal, they 
walk along on all fours.

But, when we stood up on our hind legs 
millions of years ago, here in Africa,

we freed our hands from the business of walking. 
We freed them from the chore of locomotion

and that was what enabled them to become the 
flexible, gesticulating hands that we have today.

In order to appreciate what an immense impact 
the simple act of standing up had on our

primeval ancestors, it's only necessary to 
watch our nearest relatives the chimpanzees.

When they're moving about in their natural 
habitat their hands still have to function

much of the time as 
plodding front feet.

And this prevents them from becoming highly 
developed as expressive organs of gesture.

Their front feet can operate successfully as 
grasping hands, for example, when holding a baby.

But, they never develop the subtlety of 
movement that we see in our own species.

Elegant gesturing remains the prerogative 
of the uniquely bipedal, naked ape.

So far, all the gestures that I've described 
have been regional and they're used consciously

to replace speech like the deliberate 
directions of this policeman.

But, there's another type 
of gesture all together,

unconscious hand movements usually 
referred to as gesticulations.

Instead of replacing speech, 
they accompany it.

This type of hand signal has been 
christened the baton gesture

because it beats time to our words 
and emphasizes the points we are making.

But, baton gestures do more than merely beat 
time, they also indicate our changing moods.

The posture of the hand as it beats the air 
revealing the emotional state of the speaker.

Here at Speakers' Corner in London's Hyde Park a 
veritable gallery of human baton gestures is on display.

Let's watch for a moment.

Now let's take a closer look at two of his 
gestures. Slowing it down, his first gesture is

a repelling action using his hand as if 
it were pushing away the intruder,

but without making physical contact. This 
is obvious enough, but what's he do next?

As the intruder leaves he draws his chosen audience 
back towards him using an "air grasp" gesture.

There.

Another speaker is about to mention a precise 
date and unconsciously accompanies this with a

precision gesture, as if holding a small object with 
great delicacy between his thumb and forefinger.

A third speaker is in a more aggressive mood. 
He's using, not a precision grip, but a power grip.

Thrusting his clenched fist at the audience. The 
power of his fist reflecting the power of his argument.

But, now he switches to the raised forefinger, beating his 
listeners over the head with his small, symbolic club.

And finally, he extends his hands palm-up in an 
imploring gesture, begging them to agree with him.

By contrast, this speaker employs the palm-down 
gesture, a more dominant action in which he

attempts to calm his audience by symbolically patting 
them on the head, as if they're unruly children.

Finally, this man introduces 
the "hand chop" gesture.

A decisive gesture in which he symbolically tries to 
cut through the argument as if with a sharp blade.

The urge to express our emotions with our hands 
is so strong that we continue to gesticulate,

even when the person we are talking to is miles 
away at the other end of a telephone line.

The urge to communicate by body language is 
so deeply ingrained that if we happen to be

Japanese we even bow respectfully to 
our remote, invisible companion.

But, there's another whole facet of body language 
that conveys our emotions with even greater subtlety.

We humans have the most expressive faces in the 
entire animal kingdom. We take our expressions for

granted, but if we trace them back to their 
origins it's interesting to see how they evolved.

The Chimpanzee's face is almost as expressive 
as the human's. If we watch these apes in the

wild we can begin to see how we 
acquired our own highly mobile faces.

Originally, facial muscles were needed not for 
communication, but for other more basic functions.

To move the lips for instance, improving their role in 
drinking and feeding. As the apes suck, chew and bite,

their powerful, sensitive lips explore each 
object as it comes in contact with the mouth.

This involves a great deal of pulling and stretching 
and when they're young, the infant apes

employ their long lips as valuable sucking organs, 
squeezing milk from their mother's nipples.

But, even the Chimpanzee is no match 
for the rubber-faced human being.

[laughter]

>>First, I will show you 
how I kiss my girlfriend.

>>In Cumberland, they elected Albert of Somerset,
County Tatem, "Ugliest Man in the World."

>>[Narrator] If we could see below
the surface of the human face,

we'd discover the most complicated 
set of facial muscles in the world.

These muscles give us a 
huge range of expressions.

Some big and bold, 
others extremely subtle.

But, Humans and Chimps don't just share a flexible 
face. We also share many of the same expressions.

It's not hard for us to appreciate that these young apes 
are in a playful mood by simply looking at their faces.

And if we watch the way in which Chimps 
work themselves up into a violent mood,

it's easy for us to understand what's happening.

Whenever an animal goes on the attack, 
it's always slightly fearful of retaliation.

As a result, we see a face in conflict. The 
tightness of the lips around the mouth is a

sure sign of primate aggression, while the 
lowered eyebrows indicate that the attacker

is protecting its eyes in case of a fight.

The same tight-lipped face is also seen in our own 
species in moments of great emotional intensity.

And there it is, the tight mouth of anger.

This leaves no doubt as to the mood of these women, 
especially when combined with an intense stare.

One of the most primeval of all facial 
expressions is the staring eye.

It's something we share with other animals 
and it's always threatening. Because of this,

in earlier centuries, people thought there 
was something they called the "evil eye."

A mystical force that by staring 
at them could do them harm.

To protect themselves against this evil 
eye they would often try to "out stare" it.

To do this they made effigies of eyes which were 
unblinking and could perform a permanent stare

to frighten away the evil spirits. Fishermen when 
they went to sea wanted to protect their boats

and they did so by giving 
their boats a staring eye.

And all over the Mediterranean,

fishing boats are protected with elaborately 
painted and eternally unblinking eyes.

Because hard stares are so assertive, some military 
and prison rituals employ them in a special way.

At this correctional camp in Maryland, these 
prisoners are forbidden to stare, even to glance,

at their prison officers. The officers, who 
are not allowed to lay a hand on the prisoners,

make their dominance felt by the most 
direct and intense staring they can muster.

And the effect is one of acute intimidation 
and almost painful humiliation.

>>[Officer] Inmate Williams.
>>[Inmate Williams] Sir.

>>[Officer] Can you hear me, Inmate Williams?!
>>[Inmate] Sir, yes sir!

>>[Officer] Count off, Inmate Williams!
>>[Inmate] Sir, yes sir!

>>[Officer] I'm on my toes! Sound off!
>>[Inmate] Sir, yes sir!

>>[Officer] I don't want to see an eyeball on 
me, no where near me! If you don't hurry up

I'll put your butt outta here! Don't look 
at me! And you better stop pressing me!

I don't give a crap about your attitude today. 
[inaudible] Don't care about your attitude.

You, goddamn dummy over there! Why you won't 
look at me, huh?! [both officers yelling]

>>[Second officer] That's all you gotta do! 
Quiet! Ain't nobody asked you to come here!

Ain't nobody going to beg you to stay.
>>[First officer] Put your legs together!

>>[Narrator] If you thought that staring was pretty 
intimidating, there's one culture that takes it even further.

This is the Maori Haka, the aggressive challenge 
of the indigenous people of New Zealand.

An ancient threat display still 
employed today in a modern context.

Taking another look at those aggressive 
Chimpanzees, what happens if they start to

become alarmed and fearful, if their 
courage begins to dessert them.

As they become more and more afraid, their 
expressions undergo an important change.

Their mouth corners are pulled 
back further and further.

This is the typical fear face of all 
primates, including our own species.

The best way to prove just how closely we share 
this expression is to examine the faces of the

panic-stricken customers on the latest 
fairground terror ride, the spiraling Nemesis.

Just as with frightened Chimps, these mouth 
corners are pulled back, exposing all the teeth.

The strange feature of this expression is that 
it looks, in some respects, like the human smile.

Smiling is a uniquely human expression that 
has evolved from the ancient fear face.

This might sound odd because we think 
of smiling as friendly, not fearful.

But, there's a crucial 
link between the two.

The fear face is sometimes used as a submissive signal 
saying "I'm scared, therefore I'm not a threat to you."

In other words, it's 
an anti-aggressive action.

It's only a small step from "I am not aggressive" to "I 
am friendly" and that's how the human smile evolved.

Because of the smile's anti-aggressive origins, 
witnessing it makes onlookers feel at ease and

responsive to the smiler.

For this reason it's been a mainstay of 
commercial advertising for many years.

>>Certs is a candy mint.
>>Certs is a breath mint.

>>Stop, you're both right. New Certs is two mints in 
one. Stops bad breath in seconds. Tastiest mint of all.

>>[Narrator] The problem for these 
professional smilers however, is that

it's difficult to fake the expression perfectly. 
The fixed smile gives the game away.

For synchronized swimmers, the physical 
exertions of their sport make it even harder

to fake a convincing smile. They have to keep on 
smiling to impress the judges, but it's not easy.

One of the best places to observe the false smile is on 
the faces of beach-side photographer's customers.

>>[Photographer] That's it. Beautiful. 
Just a bit more. Beautiful. Smile!

Come on. Smile.

>>But, how precisely do we know that this 
smile falls short of being convincing.

The essential feature is the specialized muscles 
that pull the mouth corners up and the ones

around the eyes that create the "smiling eyes" 
are both much harder to control consciously

than the more ancient ones that 
simply pull the mouth corners back.

No matter how hard we try, we can't 
fabricate the perfect smile.

This incredibly strong link between our facial 
expressions and the inner workings of our body

has been put to very good use by 
imaginative doctors in America,

who've taken the radical step of 
clowning in hospital wards.

>>[Clown] I think you're having a 
little too much fun, you know.

You're having so much fun they might kick you 
out of here or something like that. [laughter]

Look at all the stuff you got in here. 
You've got a lot of great stuff.

>>[Narrator] And though this may appear to be a bizarre 
form of medical care, it's impact is extraordinary.

By making patients smile and laugh, their pain 
levels are reduced. Their happy facial expressions

actually release endorphins, the body's 
natural pain killers, into their systems.

[patient laughing]

>>[Clown] We'll wait for later to do that.
>>[Patient] Please come back.

[laughter]

>>Oh, you broke his head! Oh boy! 
I think you should be a doctor like me.

>>[Narrator] Amazingly, the laughter created by 
this clowning works as well as any painkilling drug.

Such is the power of 
human body language.

[Laughter]

Because of our body language that reveals our 
true feelings, we often try to suppress it,

to hide our fears and anxieties, 
our longings and our hostilities.

But, it's such an efficient communication system 
that we usually give away a few telltale signs.

Now for most of us that's an everyday social challenge. 
For some people it's much more than that.

For professional poker players, the 
suppression of body language is a way of life.

For them, even the tiniest hint 
of emotion can cost a fortune.

Here at the annual world poker contest 
in Las Vegas, a million dollars in cash

is piled onto the table to be won or 
lost on the final play of the cards.

The finalists around the table are the best 
players in the world and needless to say,

they are masters of body language control. 
They epitomize the so-called "poker face,"

but even they are not entirely immune 
to the urges of human body language.

Careful studies of the telltale signs of poker players 
have revealed that there are several vital clues

that can tell you when a hand is good or bad, 
and when a player is bluffing.

When a player has a bad hand he 
stares at his cards a little longer.

When a player has a good hand 
his blink rate increases slightly.

When he has a good hand he 
looks away for a split second.

When he has a bad hand 
he bets with a flourish.

But, these particular players, world champions, 
in addition to being able to suppress their own

facial expressions and 
their telltale gestures,

are also masters of reading the 
body language of their competitors.

And this is the victor, but watch his face. 
This man has just won a million dollars,

but his expressions are so tightly under 
control that even now he can't show any emotions.

There's no smile, no shouting for joy, 
his poker face is like a mask.

All he allows himself eventually is a little 
jab in the air with a triumphant forefinger.

Most of us would make poor poker 
players because we're so bad at lying.

We give away our true feelings 
despite all our efforts to conceal them.

This woman has just been accused of stealing 
somebody's purse and just by looking at her

body language it's possible to spot certain 
clues that suggest that her denials are false.

>>[Accused woman] See I have one like that too.
>>[Accuser] Yeah, this is mine.

>>[Accused woman] Well, then mine 
is in your car or something.

>>[Officer] Let's see your ID.
>>[Accuser] We can look in my car if you want.

>>[Narrator] She brings her hand up to her 
mouth as if to hide the lie that she's telling.

Face touching is often a 
sign of attempted deception.

>>[Officer] How'd you get the purse?
>>[Accused woman] I got a ride.

>>[Officer] Where'd you find it?

>>[Accused woman] It was on the floor 
and I automatically thought it was mine.

>>[Narrator] And she uses the "hand shrug" 
gesture, an unconscious disclaimer

that usually increases in frequency 
when lying is taking place.

>>[Officer] Well, if you thought it was yours and you 
just got through telling me... [woman starts to argue]

>>And her eyes blink and
close more than usual.

An unconscious attempt to shut out the outside world,
to cut herself off from the tension of the lie.

>>[Accused woman] I put it in my bag and my 
bag was open, so I thought it was mine, ok.

I picked this up and this too, automatically. Ok, the 
wallet was on the floor and my mind's mixed up. OK?

He don't want the baby. 
I want the baby. Ok?

So, I just started picking up the things 
that were on the floor. I'm sorry.

>>Some people seem to think that body language 
is trivial, but it should be clear by now

that this is not the case. Indeed, at moments of 
desperation we turn not just to spoken language,

but beyond that to the more primeval language 
of the body. A signally system that was used by

our ancestors for millions of years before 
the first human words were uttered.

And one that can still play a crucial 
role in ensuring an individual's survival.

But, even more far reaching than this, body 
language is so powerful that it can change the

course of history and affect the behavior of millions 
of people. A fact that tyrants have not overlooked.

For me, body language is far more than 
just a fascinating area of human biology.

It's the core of a whole new science, the study 
of human behavior from a zoological perspective.

And for this series too, 
body watching is only the beginning.

Turning a zoological eye to our own species, 
I'll be looking at the commonplace,

as well as the more unusual 
actions of the human animal.

Why, for example, for a species which so often 
lives in a state of extreme overpopulation,

is aggressive behavior like this 
the exception rather than the rule?

In fact, for the vast majority of the time, 
the human animal goes about his business in an

amazingly ordered way. Every individual, 
even in the vast social system of a city,

is aware of fitting into a very precise 
position in the social pattern.

I'll be looking at the human 
animal's sexual behavior.

What biological mechanisms are at
work when we choose a partner?

And what influences why we find 
certain people attractive and others not?

When it comes to the courtship ritual, what 
are our species' typical behavior patterns?

And why at this time do we so often display juvenile 
characteristics such as the need to be spoon-fed?

Parental behavior, the bond between the human 
parent and its young is probably the strongest

of any species in the world.

And the effect of being separated can be 
quite devastating, especially for the parent.

What is the biological function of rites of passage, 
ceremonies that mark the arrival of sexual maturity?

And why do human individuals remain alive long 
after they cease to be able to bear children?

Finally, in this series, I'll be looking at 
those aspects of our behavior that appear to

have no parallels in the 
rest of the animal kingdom.

Is the playful behavior of our species really 
different from that seen in other animals?

Is body decoration different from the 
elaborate and colorful display plumage of birds?

What drives us to take serious 
risks merely for the thrill of it?

But, in the next episode, I'll turn my attention to 
one of our most fundamental activities: finding food.

There's no other species that consumes 
such an incredible variety of food.

In fact, we're so good at extracting 
nutrients from our environment,

that we're able to adapt to and exploit 
virtually every type of habitat on this planet.

And with our modern lifestyle, what's 
happened to our ancestral hunting urges?

Now, I've sometimes been accused of degrading man-
kind, of insulting human dignity, of making man beastly.

This surprised me because I like animals 
and I feel proud to call myself one.

I've never looked down upon them, so to call 
human beings animals is not degrading to me.

It's simply honest and putting us in our place as 
part of the scheme of nature on the planet Earth.

[music]