NOVA

NARRATOR

What are they thinking?

MAN

Oh, look at that face!

NARRATOR

Is there any way to get inside the animal mind?

MAN

What I really want to know is what is it like to be an animal, what are the problems they have to solve, and how do they think, and are they like us or are they like something totally different?

NARRATOR

They have some amazing abilities. Is it instinct, training or something else? Cutting-edge animal science reveals new answers. We put different species to the test in search of the roots of animal intelligence. Who are the best problem solvers? Who wins the battle of the super senses? In this episode, what makes an animal smart?

WOMAN

Up until a million years ago, the brainiest species were dolphins and whales.

NARRATOR

What can we learn from their language, relationships, even emotions?

MAN

If you start giving one of them grapes, then the one who gets cucumber becomes very upset.

NARRATOR

Are they more like us than we ever thought possible?

MAN

We're not the only species that has soap operas going on every day in their lives. (monkeys screeching)

NARRATOR

"Inside

Animal Minds

Who's the Smartest?" Right now on NOVA.

Major funding for NOVA is provided by the following

It's one (dog whining)

NARRATOR

Which animals are the smartest? And how did they get this way? (whistle blows) Dolphins have long been hailed as the cleverest creatures in the sea. There's no doubt they're quick learners. And in captivity, they can be trained to perform stunning tricks. Not only can they follow hand signals... but they can even learn the meaning of written symbols. (cheering) Why would a mammal that spends most of its time underwater and has flippers instead of hands have these kinds of skills? Throughout the animal kingdom, you can find creatures

with extraordinary talents

elephants with impressive memories, birds that solve complicated puzzles and tool-making chimpanzees. They inhabit utterly different worlds and come in a wide variety of shapes and sizes. But is it possible that these animals could all get their smarts in similar ways? Because whether they walk, swim or fly, the cleverest animals on earth, including us humans,

seem to have one thing in common

we live in groups. So could social living be the key to creating the most powerful minds? Around the world, animal researchers are trying to find out. And this is one of their favorite subjects. (cheering) Everyone knows that dolphins can put on incredible shows. But their greatest performances take place far from the crowds because here in the wild, these animals execute the most amazing tricks when they work as a team. In these shallow waters off the coast of Florida, dolphins band together to get the better of fast-moving fish. Here's how their trickery works. One dolphin swims in a circle. It whips up a wall of muddy water, corralling any fish inside. Three other dolphins wait just outside the ring of mud. As the fish try to leap out of the muddy ring and escape, they jump right into the open mouths of the waiting dolphins. Soon, a dolphin swings around again to create another corral. They seem in perfect synch, as if they've planned every move together. But what's really going on? Are they strategizing and communicating with each other the way we would? Or are they simply drawn together on the hunt by pure instinct? One big reason to suspect

that something more complex is going on is this

the dolphin brain. When you look at the size of most animal brains, there's usually a pretty direct link to the size of their bodies. The bigger the body, the bigger the brain. But some animals defy expectations. Humans have much more gray matter than other animals our size. So do chimps and whales. And so do dolphins. So how did their brains get big?

LORI MARINO

The $6 million question has always been, why do dolphins and whales have such large brains?

NARRATOR

Neuroscientist Lori Marino is trying to answer that question by hunting down some very ancient clues. She travels all over the country, studying fossils to trace the evolution of the dolphin brain

MARINO

One of the things that we wanted to find out with this research was exactly when they got their large brains.

NARRATOR

Here at the Smithsonian Institution, she and her colleague Mark Uhen are examining fossil skulls

of the dolphin's ancient ancestors

early whales called archaeocetes. Some archaeocetes were huge, ferocious predators with gigantic teeth. Compared to modern dolphins, their bodies were massive. Growing up to 55 feet long, in their day, nearly 40 million years ago, they were the biggest animals on Earth. Today, examining fossil skulls of early whales, Lori is trying to estimate the size of the brains that once sat inside. In ancient fossils, the space where the brain was housed is often filled with sediment. But a CT scan can see through the sediment and reveal the exact dimensions.

MARINO

We were absolutely thrilled to see the results of the study because it gave us information no one had before.

NARRATOR

When Lori examines the CT scans of this giant killer's skull, she discovers not everything was big.

MARINO

This animal had a very big body and a very small brain.

NARRATOR

But a few million years later, things started to change.

MARINO

Something happened, and what we see is a shift.

NARRATOR

When Lori looks at more recent dolphin ancestors, dating to about 30 million years ago, she discovers, in evolutionary terms, a fairly sudden shift. Bodies and teeth shrank, but at the same time, brains got bigger. The brain of the early dolphins and whales increased in size, sometimes manyfold. The dolphin brain got big and stayed that way. In fact, for millions of years, until early humans came along, the dolphin had the most powerful brain on the planet.

MARINO

Up until about a million years ago, the brainiest species on the planet were not primates; they were dolphins and whales. And we are just a very recent kid on the block.

NARRATOR

The question is, why did the brain change?

MARINO

Everyone would like to know why there was this shift in relative brain size with dolphins. It really is a mystery. It suggests that they embarked on a very different evolutionary path than their ancestors.

NARRATOR

Lori thinks that path was a social one. No longer giant, toothy beasts, individuals could increase their chances for survival by joining forces.

MARINO

Perhaps they needed to hunt together, to band together against predators, so these new animals were smaller and not as formidable. They kind of needed each other.

NARRATOR

Today, more than 30 different kinds of dolphins swim the seas, including the bottlenose dolphin, the spotted dolphin and the orca, or killer whale, the largest of all dolphins. Most live in groups, or pods, usually of a few dozen individuals. Sometimes, pods will come together, forming a mega-pod numbering in the hundreds or thousands. It seems clear that today's dolphins need each other, but why would they need big brains, too? To find out, we need to dive deep into the dolphin world... Here, in the Caribbean waters near the island of Bimini. Okay, Al, we're ready when you are! Researchers Kathleen Dudzinski and Kelly Melillo Sweeting have spent years tracking wild spotted dolphins, carefully observing and recording their interactions, trying to decipher the secrets of dolphin society. Today, the scientists encounter a gathering of dolphins swimming together. There are about 16, of mixed sexes and ages.

KATHLEEN DUDZINSKI

What we definitely saw was a socializing group of dolphins. They were interacting, playing, they were affectionate with one another.

NARRATOR

By observing these dolphins year after year, researchers are beginning to get a clearer picture of what dolphin society is really like. Compared to many land mammals, dolphin society is extremely complex and dynamic, and many of the relationships they form might surprise you. The only connection that follows a predictable pattern is the one between a mother and her calf. Among spotted dolphins, the two will stay together for about three years, until the youngster is weaned. After that, almost anything goes. Males and females who mate don't form long-term relationships. But sometimes adult females do and help each other out with babysitting duties.

KELLY MELILLO SWEETING

"White Blotch" was one adult female that we saw very consistently for ten years, and she was notorious as what appeared to be a babysitter. She'd come to the boat with her own calf and she'd have two or three extras in tow. And we know they only have one calf at a time, so it was a very clear example of that babysitting and taking turns.

NARRATOR

And it's not just the females who form close relationships and collaborate to make life easier. Male dolphins compete with one another to find mates, but sometimes two or three males will form an alliance to work together, to hunt and to attract females. Often these relationships last for many years, even entire lifetimes.

DUDZINSKI

I do believe that dolphins have friendships and favorites and that their social interactions are developing the friendships that they might have that might last a lifetime.

NARRATOR

Those in close relationships keep in touch-- literally-- by tapping each other's pectoral fins. But even if they're in some kind of alliance or friendship, dolphins like these will regularly mingle with others. This flexible social structure is known as a "fission-fusion" society. Human society is also fission-fusion. During an average day, we will move from small family groups to larger groups of colleagues to mid-size gatherings of friends. Dolphins form all sorts of relationships, just like we do. And they change over time. It's a complicated and bustling social world. And it's this social complexity that some scientists think could hold the key to the evolution of bigger brains.

MARINO

When you're a social animal, there's a lot that you need to keep track of. There's all kinds of relationships, all kinds of interactions, hierarchies, collaborations that may occur. There's a very nice relationship between social complexity that you observe in a species organization and the size of their brain.

NARRATOR

So how do dolphins use their big brains to navigate their social lives? Is it possible that some of that brain is powering a complex system of communication? After all, whenever dolphins get together, the water can get very noisy. (dolphins clicking)

Dolphins make all kinds of sounds

fast-paced clicks that sound like a creaky door... (clicking and creaking) Loud outbursts that resemble squawking birds... (loud clicking) And high-pitched whistles. (whistling) For decades, researchers have been trying to figure out what it all means. But in the 1960s, one controversial scientist took an alternative approach. Neuroscientist John Lilly was convinced that dolphins were much more intelligent than people had previously thought.

DIANA REISS

John Lilly was a neurophysiologist who was the first to really suggest that dolphins might be highly intelligent. He was the first to really sort of light the fire and get a lot of us interested. He talked about them as humans of the sea. And I just want to talk to such ancient characters and find out, you know, if they have any wisdom for us.

NARRATOR

Rather than deciphering their language, Lilly decided the quickest route to communicating with dolphins would be to teach one of them how to speak English. And he set out to do just that, with one of the strangest animal experiments ever devised.

REISS

John Lilly did an experiment that involved building a dolphin house. And what he did was he bought property and he flooded the first floor so the dolphin could actually live in this first floor area.

NARRATOR

With the dolphin, named Peter, living in less than four feet of water, it wasn't a very humane approach. But the idea was to keep Peter in close contact with his teacher.

REISS

He actually had a woman living there with the dolphin in a very intense time, where she tried to teach this dolphin English.

NARRATOR

The young woman was Margaret Howe, and she lived, ate and slept here for two and a half months, trying to teach Peter every day. This is a sound recording of Margaret counting while Peter attempts to imitate her.

MARGARET

One, two, three, four, five. (Peter squeaks five times) One, two, three, four, five, six. (Peter squeaks rapidly)

NARRATOR

It's safe to say the dolphin house experiment was both unethical and a complete failure.

REISS

What the dolphins did was not English. They could imitate the numbers of syllables they were hearing, but they couldn't formulate English. They don't have the same kind of articulatory system we have.

NARRATOR

In spite of its shortcomings, Lilly's work got a lot of attention and inspired the Hollywood film The Day of the Dolphin. What do you know about linguistics? The fictional scientist, played by George C. Scott, seemed to have better luck teaching his dolphin to count "one, two, three" in English than John Lilly ever did.

DOLPHIN

One... Two...

NARRATOR

For real-life scientists, Lilly's work showed that any idea of teaching dolphins human language was probably a fantasy. Today, researchers are focused intently on trying to decipher the dolphin's own system of communication, and they've been using underwater microphones to record all those clicks, squawks and whistles, hoping to find patterns and discover what they actually mean. But there's a problem. Dolphins make sounds underwater by vibrating tissues in their nasal cavities, a bit like the way we humans vibrate our vocal cords. They usually don't open their mouths or make any visible signs.

JUSTIN GREGG

Dolphins are essentially ventriloquists. They produce sound and you can't see anything. Nothing changes on their facial expression, or even their blowholes. So they can be making sounds without moving, and you have no idea who made the sound.

NARRATOR

But now researchers have come up with a pioneering new technique to listen in on dolphin conversations.

VINCENT JANIK

We're going out today to try to find wild dolphins and attach tags to them.

NARRATOR

Biologist Vincent Janik is on a quest to eavesdrop on wild dolphins and try to decipher the dolphin communication code.

JANIK

They are little recording tags that can give us information about their sounds that they're making and also give us information about their behavior as they're in the bay, their own wild environment.

NARRATOR

Today, a bottlenose dolphin's been captured in shallow water. Are you going to put the acoustic on? The researchers work rapidly to minimize distress to the animal. To solve the problem of capturing the exact sounds made by a particular dolphin, Vincent's team uses suction cups to attach a recording device directly to the animal's head. It's small enough for a dolphin to ignore. Nicholas, Nicholas, get signal? Roger that. Okay. If it were uncomfortable, the dolphin could easily use the seabed to knock it off. It will now record all the sounds that the dolphin makes and, using GPS, will keep track of its movements. The dolphin's released and soon joins some other tagged dolphins. The scientists will constantly observe them so later they'll be able to match their behavior to the sounds they're making. What's going on over there? There's lots of splashing. I think that's a dorsal fin. Yeah, they're two dolphins.

JANIK

What we can look at is what the animal's doing-- whether it's traveling, whether it's foraging, whether it's socializing with others. Those kinds of things we can observe from the surface.

NARRATOR

After a few hours, the devices fall off on their own and float to the surface so the team can retrieve them and begin analyzing the dolphin's sounds. (clicking and squeaking) At first hearing,

it's a cacophony

a whole range of dolphin clicks, whistles and pulses. (creaking) Today, we know that the creaky-door clicks are the sounds dolphins use for echolocation. They work like sonar pings. Dolphins listen for the echoes of the clicks as they bounce off objects in their environment. This plays a crucial role in helping them locate their prey and navigate in murky water.

But Vincent is interested in other kinds of dolphin sounds

the ones they use for communication. Sometimes,

there are patterns

certain sounds consistently made when a dolphin is doing a particular action, like this one. (braying)

JANIK

One sound that we've found is the so-called bray sound, which dolphins produce when they find fish. (braying continues) And it's a sound that brings in other dolphins as well. (braying continues)

NARRATOR

And when dolphins are aggressive, playful or not, they often produce lower frequency sounds known as burst pulses. (clicking) These kinds of calls are common in the animal kingdom. But there is one kind of sound dolphins make that is much more unusual. It's called the signature whistle. (whistling)

JANIK

Every dolphin has its own signature whistle that's different from all others. So within a population, you have very, very different whistles for every animal. The function of the whistle really is to broadcast its identity and also to stay in touch with other group members. The closest in our language perhaps is really if I would say, "I'm Vincent and I'm over here."

NARRATOR

Dolphins have good vision, but if the water is murky or individuals get separated, Vincent believes they use signature whistles to help keep a group together.

JANIK

If an animal gets lost, it will also produce that whistle to try to make contact again, and that's something that we often see between mothers and calves. When the calf wanders off and is far away and eventually wants to get back to the mother, what it does is it starts to produce its signature whistle.

NARRATOR

It is rare for animals to have unique calls that correspond to particular individuals, but dolphins aren't the only animals to use vocal calls as a way of identifying each other. One other animal known to do this inhabits a world completely different from the dolphins' underwater domain. The Amboseli National Park in Kenya

is home to some of the most social animals on the planet

elephants.

KAREN McCOMB

The thing about this park that's outstanding is the visibility of the elephants, a population of more than a thousand elephants, which we know individually.

NARRATOR

Karen McComb has been observing elephants here for decades, trying to unlock the secrets of elephant society and communication.

McCOMB

It's being able to get inside animal minds, get into a social world that's actually rather different from ours that will tell us what elephants are really thinking.

NARRATOR

Elephant society is a family affair, especially for females. They stay with their mothers, sisters, aunts and cousins for their entire lives. The oldest female, known as the matriarch, is the leader. Young males stick with their mothers until they're about ten years old, and then they leave the social group to live independently. And elephants are always on the move. Elephants have this really unusual and complex social system. So instead of just staying put and communicating with their immediate neighbors, they sort of move in relation to one another in a very fluid, fission-fusion way. Females and young males spend time with lots of elephants in groups of different sizes. And they communicate with dozens of different kinds of calls. Some rumbles are such low frequency they're out of range of human hearing, but elephants can detect them from miles away. Karen believes that their calls are crucial for the elephants to keep track of friend and foe.

McCOMB

They'll come into contact with many, many other families as they move and feed, and they will be making decisions about which families it's safe to feed next to and which they should avoid.

NARRATOR

To find out how elephants make those decisions, Karen designed an experiment. It involves years of painstaking research and some very powerful speakers. Karen has made a library of elephant contact calls and is going to play some to a group of elephants who are on the move and see how they react. First, she plays a call from an elephant from a different group, but a friendly one. (low, rumbling call) The elephants just keep on walking and their behavior doesn't change. But when Karen plays a call from an elephant they don't know well, their behavior is very different. (higher, more abrupt call) The elephants abruptly stop their march. They turn toward the unfamiliar voice, gather closer together and move directly toward the sound in what Karen says is a defensive show of force. Karen tested 21 families and found that the elephants consistently distinguished between friend and stranger, recognizing up to 100 different voices. She believes that a lot of their brain power and memory

is going into keeping track of otherlephants

the ones they do and do not know. Who is safe to be around and who might pose a threat? And it could be the same with us.

JUSTIN GREGG

We have these relationships that we need to maintain throughout our lives with friends and enemies. You have to remember who owes you a favor. And that sort of complexity seems to go hand in hand with the evolution of larger brains.

NARRATOR

It's not enough to be simply social. The animal world is full of social creatures, and plenty of them have some of the tiniest brains around.

GREGG

There's lots of different kinds of social behavior of social animals. Insects, for example, termites and ants are extremely social, and they can't live by themselves. They need each other for everything that they do.

NARRATOR

Ants live in colonies, sometimes with millions of members, and divide labor between workers and soldiers. The collective might of termites can result in the construction of huge, elaborate mounds. And social living, along with an intricate communication system, is crucial to bees, with tens of thousands of individuals working together to find food and raise their young. All these animals are highly social, and together, they can accomplish wonders. But each individual has a miniscule brain.

GREGG

Ants are always essentially working together

toward one goal

to help each other out to make the colony a success. Now, dolphins are on the other end of the spectrum. Sometimes they cooperate, sometimes they are competing with each other. So when you enter this element of both cooperating and competing at the same time in order to survive, this new kind of social complexity and intelligence blossoms.

NARRATOR

Cooperation and competition, side by side. This is the recipe for a really complicated social life. And animals who live this way often have big brains. But whether one leads to the other is still unclear. Part of the challenge for scientists is figuring out how much animals like dolphins might understand about their social lives. Dolphin cognition expert Diana Reiss has spent years trying to find out. She works with dolphins at the National Aquarium in Baltimore. Keeping dolphins in captivity is controversial, and aquariums in the U.S. haven't captured wild dolphins for two decades. Diana believes it's only in the controlled environment of aquariums that you can unlock some of the secrets of the dolphin mind. Here, she can carry out experiments not possible in the wild. The aquarium has an observation chamber, nicknamed "The Pit." It's cramped. But from here, Diana has an excellent view of the dolphins' underwater behavior. This dolphin is making bubble rings, a behavior observed both in captivity and in the wild. A dolphin blows out an air bubble from its blowhole, then flicks it with its tail to create a ring shape. Bubble rings appear to have no practical purpose, except for entertainment.

It's another dolphin behavior we can relate to

the ability to play. Diana wants to find out what else we share on an even more fundamental level. She's investigating whether dolphins recognize themselves as individuals. Do they each have a sense of self? Diana places a one-way mirror inside the observation window.

DIANA REISS

So now we're looking through a window and they'll be seeing a mirror.

NARRATOR

The dolphins can't see people inside The Pit. All they see are their own reflections. Dolphins don't behave like this, staying in one place and staring, if they simply meet another dolphin. Another extremely unusual action is this curious fin wiggling.

REISS

This looks nothing like what they do when they're socially interacting with another.

NARRATOR

They also look inside their mouths or closely at their eyes.

REISS

They perform all sorts of odd behaviors much like we might do in front of a mirror to see what we look like when we do that new dance step or when we just want to see how we look in a new outfit.

NARRATOR

They seem to be using the mirror like a tool to see parts of their bodies that are usually out of view. This all supports the idea that dolphins must be aware they're looking at themselves. Dolphins share this ability to recognize themselves in a mirror with just a few other animals. Elephants do it. So do chimpanzees. But the vast majority, including dogs, don't. And interestingly, neither do young humans. Before they're 18 months old, most children fail to point out a red dot painted on their cheek. This boy assumes he's looking at another child. Only when they're about two does a child first realize that the mark is on her own cheek and she knows the reflection is of herself. Eventually, a human child's self-awareness will go far beyond recognizing her own body in a mirror. She'll be aware of her own thoughts and be able to contemplate the thoughts of others. But is the same true for other animals, like dolphins? Diana thinks it might be.

REISS

Having a sense of self would go hand in hand, I could say flipper to flipper, with complex understanding of others.

NARRATOR

So if animals like dolphins recognize themselves as individuals, how much do they understand about the other creatures around them? It's a question debated by animal researchers.

BRIAN HARE

The big question is not, "Do animals think?" The big question is, "Do they think about others thinking?"

NARRATOR

"Thinking about others thinking" is something we humans do all the time. As humans, we are remarkable e we can imagine what it's like, in some context, to be someone else. That's an amazing ability that we see in humans. This ability we have to imagine what it's like to be another person is known as "theory of mind."

ALEXANDRA HOROWITZ

The theory of mind is the idea that all humans normally develop an understanding

that other people have different minds than our own

that what I know is different than what you know and that what I want is different than what you want.

And that's a big question for animal researchers

whether any non-human animal also eventually, or at all, develops a theory of mind.

NARRATOR

It's extremely difficult to prove that an animal "thinks" about other animals' "thoughts," but some of the most interesting research has been done

with our closest relatives

the chimpanzees. Primatologist Frans de Waal works with chimpanzees at the Yerkes Primate Center in Atlanta. When an animal like a chimp is aware that another chimp has a different perspective on the world, it could give it an advantage. Chimpanzee groups have a strict ranking system.

At the very top is the most powerful chimp

the alpha male. He's in charge of the group, and every other chimp has a position of rank below him, from the most dominant to the most subordinate. Frans has set up an interesting experiment to find out how a low-ranking animal behaves when it gets valuable information that a more dominant member does not know. Could one chimp actively deceive another? Most studies that are on deception are observational, anecdotal studies. But nowadays, we do experiments also on it, and so you can, for example, hide food. One chimp knows where it is, the other one doesn't know where it is, and then you can see if deception goes on between them.

The experiment involves two chimps

Rita and Missy. Rita is the more dominant. At the start of the experiment, the chimps are in their sleeping quarters. One of the keepers goes into the outdoor enclosure and hides a banana under the red tube. Missy is allowed to watch through a window, so she sees the keeper hide the banana. Rita can see Missy watching through the window, but she can't see what's going on outside. Then they let the chimps out. Rita, the dominant chimp, comes out first. If she knew where the banana was hidden, she'd simply help herself. But only Missy, the subordinate, saw the banana being placed under the red tube. Rita just saw Missy watching. So the two have very different perspectives on the same situation. Missy notices Rita close to the food and sits on top of the tube. She seems to be playing it cool. Rita now wanders off. When she's far enough away, Missy goes for the banana. Frans believes that Missy has successfully deceived Rita. He's observed this kind of behavior in chimps, but it's rare in other animals. So if animals can deceive others, what would that say about their minds?

REISS

When we think about deception, you have to sort of understand the rules of the game. Deception is manipulating the rules of the game, so a highly social animal who understands the rules of the game and then changes it somehow for its own benefit or to make a joke, perhaps, or to achieve something shows a level of sophistication.

NARRATOR

We humans are very good at it. So, are the most successful animals natural born liars?

HARE

If you live in a complex social group, you're competing against others who eat the same thing you do, who mate with the same individuals that you might want to mate with, so if you can somehow manipulate the behavior of others, then you're going to have potentially a competitive advantage.

NARRATOR

But social living is not just about lies and deceit. Deception can only get you so far. There's a big disadvantage to deception and that's why it is not so often used, is that if I do that too often to you, you may catch on and at some point, you don't trust me anymore. Frans believes that primates, as they negotiate their social lives, are very aware of the competition. And so he's come up with another experiment, this one to test their sense of justice. Do they realize if they're being treated fairly or not, compared to others? Normally, you would think the only thing an animal should care about is, "What do I get for my task? I work, I get rewards." But no, they're comparing with what the other one is getting. Frans begins the fairness test with the capuchin monkey. These small, clever animals are kept in large enclosures, but for the short duration of the test, they're in a lab area.

Each monkey carries out a simple task

they have to give a small stone to the experimenter in exchange for a reward. When both get a reward of cucumber, everyone's happy. But watch what happens when the one on the right receives a grape reward instead.

FRANS de WAAL

If you start giving one of them grapes, which are far better than cucumber, then the one who gets cucumber becomes very upset and becomes agitated-- emotionally agitated. (loud banging)

NARRATOR

It turns out quite a few creatures, including ravens and dogs, will protest if they get the short end of the stick, as if they know that they're being treated unfairly. But what about a concern for injustice for the other guy? Research with one of ourlosest relatives, a highly social chimp called a bonobo, is revealing some surprises. At the Lola ya Bonobo orphanage in the Congo, animals spend most of their days in the forest, but come inside for short periods of time for experiments like this. One bonobo is inside an enclosure. The door is locked and can only be opened from the other side. Here, another bonobo-- a stranger-- is given a delicious pile of fruit. So what will she do?

HARE

We recently discovered that bonobos can share with strangers-- that they actually will sacrifice their own food for the opportunity to interact with another bonobo they've never met before. That's not something that we thought another species would do. When we think about nature as red in tooth and claw, that you would share with somebody you don't share any genes with, that's not in your family, they're not even in your group? I thought that was something that humans did. So the fact that a bonobo does that is remarkable. It's the closest thing that you can think of to doing charity in animals.

NARRATOR

Among the most social animals, there's growing evidence for active concern for the well-being of others. Recently, it was reported that elephants will console an animal in distress by gently touching it with their trunks. And elephants do something else which might demonstrate powerful feelings of connection to others of their species. Elephants, through observational evidence, seem to have a really unusual interest in the dead of their own species, either fresh carcasses or skulls. The very interesting thing is actually the interest seems to persist after death. Karen McComb has devised an experiment to find out more. She takes the skulls of elephants killed by poachers to make a miniature graveyard in the path of an approaching herd. Now she just observes.

McCOMB

Yep, I think we've definitely got the beginnings of a reaction here. Some of the younger females starting to respond. They've picked up a whiff of the skulls. The male is swinging his trunk towards the skulls and the jawbones as well.

NARRATOR

A few animals, including chimps, will be curious about the corpse of a companion, touching and investigating the body. But only elephants take an interest in the skulls and bones of their own kind long after death.

McCOMB

We've got the females clustering around the skull, touching the jawbones. You see the way the ends of the trunks are moist there? That's enhancing the scent that they're getting. You wouldn't see that in any other species, except for humans.

NARRATOR

To test whether this intense response was specific to elephant skulls and not just a reaction to a new object, Karen has done exactly the same thing with skulls from other animals.

McCOMB

If you present elephants with the skulls of other large herbivores, the biggest herbivores you can get-- rhino, buffalo skulls-- you do not get that level of interest. Given the choice between the three, they make a beeline for the elephant skull. And they're particularly interested actually in elephant ivory. That, they will spend a massive amount of time investigating, picking it up, carrying it off, touching it. They are definitely able to recognize, distinguish the skulls and other remains of elephants from other species.

NARRATOR

This kind of behavior seems very familiar to us humans.

McCOMB

Obviously, we are intensely involved and interested in death in the sense that our relationships continue beyond that, and it's very interesting that this highly social animal seems to also have a social interest that extends beyond death.

NARRATOR

As we watch these elephants gently touch the remains of their dead, it's impossible to know exactly what is driving their curiosity. Or whether these animals might be experiencing emotions similar to what we would feel, like grief. What scientists like Karen do know is that for highly social creatures, relationships are essential for survival. So, with so much time and brain power spent reading social situations, could these animals be better prepared to gauge an interaction with another species? One such interaction was reported not long ago in the waters near Hawaii, where a group of divers was swimming at night, photographing manta rays. Unexpectedly, a lone dolphin swims close to the divers. They notice that the dolphin is tangled in a thin fishing line and has a hook stuck in its fin. Without help, he will probably perish.

JUSTIN GREGG

And it approaches this diver as if it knows that the diver can possibly help out.

And that's in fact what the diver does

very gently cuts away the fishing line. It takes quite awhile. The dolphin actually has to go up for air and then come back down again.

NARRATOR

The entire process takes about seven minutes.

GREGG

So the question is, what was the dolphin thinking? My guess is the dolphin was just approaching the diver and then probably figured out that the diver was intending to help at that stage. So did it come swimming out of the deep to solicit a diver's help? Probably not, but it certainly was smart enough to figure out that the diver could help once the diver started helping.

NARRATOR

When the fishing line has been removed, he swims away. It is a remarkable encounter between two species. Witnessing the behavior of all these social animals, it's hard not to connect-- to see some parallels with our own complicated lives.

BRIAN HARE

Part of the experience of being human as a species is a bit lonely. And I think one of the really fun things about studying other animals is over time, we learn that actually, we're not the only really social species. We're not the only species that has literally soap operas going on every day in their lives, and we're not the only species that has many of the same problems we experience. Whether it's that, "Oh, my gosh, I have to deal with my family member "who is driving me crazy, but they're my family so I have to support them," or, you know, "Gosh, I have this friend that I like to hang out with but they keep taking advantage of me," or the fact that, "Oh, this guy who thinks he's so much bigger than me "and he can do whatever he wants, "I have to get my friends together and be nice to them so they'll help me." These are all things that we experience together with lots of other social animals on the planet, so I think it's not just trying to understand what the life of animals are like. I think part of it is that it makes us feel part of nature and that we're not here alone. There are other animals that experience things that we also experience.

NARRATOR

And it could be that these kinds of experiences, these challenges we face every day as social animals, have played a key role in the evolution of bigger and smarter brains. Because in certain situations, the creature who can cleverly negotiate, who can lend or extend a helping hand, is often the one with the best chance of survival.

HARE

I think we often think about evolution as always the biggest, strongest, most competitive individual is the one that's going to survive and reproduce. But I think we see again and again and again and again in evolution that that's not the case at all. Other times, what's going to be favored is things that lead to better cooperation so that you can work together to solve problems you otherwise couldn't solve on your own. And that requires tolerance. That requires actually not dominance, but sometimes a lack of dominance. So when we study a wide variety of species, you see things beyond just "it's always the big guy that wins."

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