9:59:59.000,9:59:59.000
In the 1980s, a bonobo named Kanzi

9:59:59.000,9:59:59.000
learned to communicate with humans[br]to an unprecedented extent—

9:59:59.000,9:59:59.000
not through speech or gestures,

9:59:59.000,9:59:59.000
but using a keyboard of abstract symbols[br]representing objects and actions.

9:59:59.000,9:59:59.000
By pointing to several of these in order,[br]he created sequences to make requests,

9:59:59.000,9:59:59.000
answer verbal questions from [br]human researchers,

9:59:59.000,9:59:59.000
and refer to objects that weren’t[br]physically present.

9:59:59.000,9:59:59.000
Kanzi’s exploits ignited immediate [br]controversy over one question:

9:59:59.000,9:59:59.000
had Kanzi learned language?

9:59:59.000,9:59:59.000
What we call language is something [br]more specific than communication.

9:59:59.000,9:59:59.000
Language is about sharing what’s[br]in our minds: stories, opinions, questions,

9:59:59.000,9:59:59.000
the past or future, imagined times[br]or places, ideas.

9:59:59.000,9:59:59.000
It is fundamentally open-ended,

9:59:59.000,9:59:59.000
and can be used to say an [br]unlimited number of things.

9:59:59.000,9:59:59.000
Many researchers are convinced [br]that only humans have language,

9:59:59.000,9:59:59.000
that the calls and gestures other species[br]use to communicate are not language.

9:59:59.000,9:59:59.000
Each of these calls and gestures generally[br]corresponds to a specific message,

9:59:59.000,9:59:59.000
for a limited total number of messages

9:59:59.000,9:59:59.000
that aren’t combined into more [br]complex ideas.

9:59:59.000,9:59:59.000
For example, a monkey species might[br]have a specific warning call

9:59:59.000,9:59:59.000
that corresponds to a particular predator,[br]like a snake—

9:59:59.000,9:59:59.000
but with language, there are countless [br]ways to say “watch out for the snake.”

9:59:59.000,9:59:59.000
So far no animal communication seems to[br]have the open-endedness of human language.

9:59:59.000,9:59:59.000
We don’t know for sure what’s going[br]on in animals’ heads,

9:59:59.000,9:59:59.000
and its possible this definition of[br]language, or our ways of measuring it,

9:59:59.000,9:59:59.000
don’t apply to them.

9:59:59.000,9:59:59.000
But as far as we know, only humans [br]have language.

9:59:59.000,9:59:59.000
And while humans speak around [br]7,000 distinct languages,

9:59:59.000,9:59:59.000
any child can learn any language,

9:59:59.000,9:59:59.000
indicating that the biological machinery[br]underlying language

9:59:59.000,9:59:59.000
is common to all of us.

9:59:59.000,9:59:59.000
So what does language mean for humanity?

9:59:59.000,9:59:59.000
What does it allow us to do, [br]and how did we come to have it?

9:59:59.000,9:59:59.000
Exactly when we acquired this capacity[br]is still an open question.

9:59:59.000,9:59:59.000
Chimps and bonobos are our closest[br]living relatives,

9:59:59.000,9:59:59.000
but the lineage leading to humans [br]split from the other great apes

9:59:59.000,9:59:59.000
more than four million years ago.

9:59:59.000,9:59:59.000
In between, there were many species—[br]all of them now extinct,

9:59:59.000,9:59:59.000
which makes it very difficult to know[br]if they had language or anything like it.

9:59:59.000,9:59:59.000
Great apes give one potential clue [br]to the origins of language, though:

9:59:59.000,9:59:59.000
it may have started as gesture rather[br]than speech.

9:59:59.000,9:59:59.000
Great apes gesture to each other in the[br]wild much more freely than they vocalize.

9:59:59.000,9:59:59.000
Language may have begun to take shape[br]during the Pleistocene,

9:59:59.000,9:59:59.000
2-3 million years ago, with the emergence[br]of the genus Homo

9:59:59.000,9:59:59.000
that eventually gave rise [br]to our own species, homo sapiens.

9:59:59.000,9:59:59.000
Brain size tripled, and bipedalism freed[br]the hands for communication.

9:59:59.000,9:59:59.000
There may have been a transition from[br]gestural communication

9:59:59.000,9:59:59.000
to gestural language—from pointing [br]to objects and pantomiming actions

9:59:59.000,9:59:59.000
to more efficient, abstract signing.

9:59:59.000,9:59:59.000
The abstraction of gestural communication[br]would have removed the need for visuals,

9:59:59.000,9:59:59.000
setting the stage for a transition [br]to spoken language.

9:59:59.000,9:59:59.000
That transition would have likely [br]come later, though.

9:59:59.000,9:59:59.000
Articulate speech depends on a vocal tract[br]of a particular shape.

9:59:59.000,9:59:59.000
Even our closest ancestors, the [br]Neanderthals and Denisovans,

9:59:59.000,9:59:59.000
had vocal tracts that were not optimal,

9:59:59.000,9:59:59.000
though they likely had some [br]vocal capacity,

9:59:59.000,9:59:59.000
and possibly even language.

9:59:59.000,9:59:59.000
Only in humans is the vocal tract optimal.

9:59:59.000,9:59:59.000
Spoken words free the hands for activities[br]such as tool use and transport.

9:59:59.000,9:59:59.000
So it may have been the[br]emergence of speech,

9:59:59.000,9:59:59.000
not of language itself, that led to the [br]dominance of our species.

9:59:59.000,9:59:59.000
Language is so intimately tied to complex[br]thought, perception, and motor functions

9:59:59.000,9:59:59.000
that it’s difficult to untangle[br]its biological origins.

9:59:59.000,9:59:59.000
Some of the biggest mysteries remain:

9:59:59.000,9:59:59.000
to what extent did language as a [br]capacity shape humanity,

9:59:59.000,9:59:59.000
and to what extent did humanity shape[br]language?

9:59:59.000,9:59:59.000
Did the vast number of scenarios we can [br]envisage

9:59:59.000,9:59:59.000
come before our ability to share them,[br]or did they evolve in concert?