2
The Tree of Knowledge
IN THE PREVIOUS CHAPTER WE SAW THAT although Sapiens had
already populated East Africa 150,000 years ago, they began to overrun the rest
of planet Earth and drive the other human species to extinction only about
70,000 years ago. In the intervening millennia, even though these archaic
Sapiens looked just like us and their brains were as big as ours, they did not
enjoy any marked advantage over other human species, did not produce
particularly sophisticated tools, and did not accomplish any other special feats.
In fact, in the first recorded encounter between Sapiens and Neanderthals,
the Neanderthals won. About 100,000 years ago, some Sapiens groups migrated
north to the Levant, which was Neanderthal territory, but failed to secure a firm
footing. It might have been due to nasty natives, an inclement climate, or
unfamiliar local parasites. Whatever the reason, the Sapiens eventually retreated,
leaving the Neanderthals as masters of the Middle East.
This poor record of achievement has led scholars to speculate that the
internal structure of the brains of these Sapiens was probably different from
ours. They looked like us, but their cognitive abilities – learning, remembering,
communicating – were far more limited. Teaching such an ancient Sapiens
English, persuading him of the truth of Christian dogma, or getting him to
understand the theory of evolution would probably have been hopeless
undertakings. Conversely, we would have had a very hard time learning his
language and understanding his way of thinking.
But then, beginning about 70,000 years ago, Homo sapiens started doing
very special things. Around that date Sapiens bands left Africa for a second time.
This time they drove the Neanderthals and all other human species not only from
the Middle East, but from the face of the earth. Within a remarkably short
period, Sapiens reached Europe and East Asia. About 45,000 years ago, they
somehow crossed the open sea and landed in Australia – a continent hitherto
untouched by humans. The period from about 70,000 years ago to about 30,000
years ago witnessed the invention of boats, oil lamps, bows and arrows and
needles (essential for sewing warm clothing). The first objects that can reliably
be called art date from this era (see the Stadel lion-man on this page), as does the
first clear evidence for religion, commerce and social stratification.
Most researchers believe that these unprecedented accomplishments were the
product of a revolution in Sapiens’ cognitive abilities. They maintain that the
people who drove the Neanderthals to extinction, settled Australia, and carved
the Stadel lion-man were as intelligent, creative and sensitive as we are. If we
were to come across the artists of the Stadel Cave, we could learn their language
and they ours. We’d be able to explain to them everything we know – from the
adventures of Alice in Wonderland to the paradoxes of quantum physics – and
they could teach us how their people view the world.
The appearance of new ways of thinking and communicating, between
70,000 and 30,000 years ago, constitutes the Cognitive Revolution. What caused
it? We’re not sure. The most commonly believed theory argues that accidental
genetic mutations changed the inner wiring of the brains of Sapiens, enabling
them to think in unprecedented ways and to communicate using an altogether
new type of language. We might call it the Tree of Knowledge mutation. Why
did it occur in Sapiens DNA rather than in that of Neanderthals? It was a matter
of pure chance, as far as we can tell. But it’s more important to understand the
consequences of the Tree of Knowledge mutation than its causes. What was so
special about the new Sapiens language that it enabled us to conquer the world?*
It was not the first language. Every animal has some kind of language. Even
insects, such as bees and ants, know how to communicate in sophisticated ways,
informing one another of the whereabouts of food. Neither was it the first vocal
language. Many animals, including all ape and monkey species, have vocal
languages. For example, green monkeys use calls of various kinds to
communicate. Zoologists have identified one call that means, ‘Careful! An
eagle!’ A slightly different call warns, ‘Careful! A lion!’ When researchers
played a recording of the first call to a group of monkeys, the monkeys stopped
what they were doing and looked upwards in fear. When the same group heard a
recording of the second call, the lion warning, they quickly scrambled up a tree.
Sapiens can produce many more distinct sounds than green monkeys, but whales
and elephants have equally impressive abilities. A parrot can say anything Albert
Einstein could say, as well as mimicking the sounds of phones ringing, doors
slamming and sirens wailing. Whatever advantage Einstein had over a parrot, it
wasn’t vocal. What, then, is so special about our language?
The most common answer is that our language is amazingly supple. We can
connect a limited number of sounds and signs to produce an infinite number of
sentences, each with a distinct meaning. We can thereby ingest, store and
communicate a prodigious amount of information about the surrounding world.
A green monkey can yell to its comrades, ‘Careful! A lion!’ But a modern
human can tell her friends that this morning, near the bend in the river, she saw a
lion tracking a herd of bison. She can then describe the exact location, including
the different paths leading to the area. With this information, the members of her
band can put their heads together and discuss whether they ought to approach the
river in order to chase away the lion and hunt the bison.
A second theory agrees that our unique language evolved as a means of
sharing information about the world. But the most important information that
needed to be conveyed was about humans, not about lions and bison. Our
language evolved as a way of gossiping. According to this theory Homo sapiens
is primarily a social animal. Social cooperation is our key for survival and
reproduction. It is not enough for individual men and women to know the
whereabouts of lions and bison. It’s much more important for them to know who
in their band hates whom, who is sleeping with whom, who is honest, and who is
a cheat.
4. An ivory figurine of a ‘lion-man’ (or ‘lioness-woman’) from the Stadel
Cave in Germany (c.32,000 years ago). The body is human, but the head is
leonine. This is one of the first indisputable examples of art, and probably of
religion, and of the ability of the human mind to imagine things that do not
really exist.
The amount of information that one must obtain and store in order to track
the ever-changing relationships of a few dozen individuals is staggering. (In a
band of fifty individuals, there are 1,225 one-on-one relationships, and countless
more complex social combinations.) All apes show a keen interest in such social
information, but they have trouble gossiping effectively. Neanderthals and
archaic Homo sapiens probably also had a hard time talking behind each other’s
backs – a much maligned ability which is in fact essential for cooperation in
large numbers. The new linguistic skills that modern Sapiens acquired about
seventy millennia ago enabled them to gossip for hours on end. Reliable
information about who could be trusted meant that small bands could expand
into larger bands, and Sapiens could develop tighter and more sophisticated
types of cooperation.1
The gossip theory might sound like a joke, but numerous studies support it.
Even today the vast majority of human communication – whether in the form of
emails, phone calls or newspaper columns – is gossip. It comes so naturally to us
that it seems as if our language evolved for this very purpose. Do you think that
history professors chat about the reasons for World War One when they meet for
lunch, or that nuclear physicists spend their coffee breaks at scientific
conferences talking about quarks? Sometimes. But more often, they gossip about
the professor who caught her husband cheating, or the quarrel between the head
of the department and the dean, or the rumours that a colleague used his research
funds to buy a Lexus. Gossip usually focuses on wrongdoings. Rumour-mongers
are the original fourth estate, journalists who inform society about and thus
protect it from cheats and freeloaders.
Most likely, both the gossip theory and the there-is-a-lion-near-the-river
theory are valid. Yet the truly unique feature of our language is not its ability to
transmit information about men and lions. Rather, it’s the ability to transmit
information about things that do not exist at all. As far as we know, only Sapiens
can talk about entire kinds of entities that they have never seen, touched or
smelled.
Legends, myths, gods and religions appeared for the first time with the
Cognitive Revolution. Many animals and human species could previously say,
‘Careful! A lion!’ Thanks to the Cognitive Revolution, Homo sapiens acquired
the ability to say, ‘The lion is the guardian spirit of our tribe.’ This ability to
speak about fictions is the most unique feature of Sapiens language.
It’s relatively easy to agree that only Homo sapiens can speak about things
that don’t really exist, and believe six impossible things before breakfast. You
could never convince a monkey to give you a banana by promising him limitless
bananas after death in monkey heaven. But why is it important? After all, fiction
can be dangerously misleading or distracting. People who go to the forest
looking for fairies and unicorns would seem to have less chance of survival than
people who go looking for mushrooms and deer. And if you spend hours praying
to non-existing guardian spirits, aren’t you wasting precious time, time better
spent foraging, fighting and fornicating?
But fiction has enabled us not merely to imagine things, but to do so
collectively. We can weave common myths such as the biblical creation story,
the Dreamtime myths of Aboriginal Australians, and the nationalist myths of
modern states. Such myths give Sapiens the unprecedented ability to cooperate
flexibly in large numbers. Ants and bees can also work together in huge
numbers, but they do so in a very rigid manner and only with close relatives.
Wolves and chimpanzees cooperate far more flexibly than ants, but they can do
so only with small numbers of other individuals that they know intimately.
Sapiens can cooperate in extremely flexible ways with countless numbers of
strangers. That’s why Sapiens rule the world, whereas ants eat our leftovers and
chimps are locked up in zoos and research laboratories.
