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In the 1980s, a bonobo named Kanzi

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learned to communicate with humans
to an unprecedented extent—

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not through speech or gestures,

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but using a keyboard of abstract symbols
representing objects and actions.

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By pointing to several of these in order,
he created sequences to make requests,

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answer verbal questions from 
human researchers,

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and refer to objects that weren’t
physically present.

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Kanzi’s exploits ignited immediate 
controversy over one question:

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had Kanzi learned language?

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What we call language is something 
more specific than communication.

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Language is about sharing what’s
in our minds: stories, opinions, questions,

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the past or future, imagined times
or places, ideas.

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It is fundamentally open-ended,

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and can be used to say an 
unlimited number of things.

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Many researchers are convinced 
that only humans have language,

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that the calls and gestures other species
use to communicate are not language.

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Each of these calls and gestures generally
corresponds to a specific message,

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for a limited total number of messages

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that aren’t combined into more 
complex ideas.

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For example, a monkey species might
have a specific warning call

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that corresponds to a particular predator,
like a snake—

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but with language, there are countless 
ways to say “watch out for the snake.”

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So far no animal communication seems to
have the open-endedness of human language.

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We don’t know for sure what’s going
on in animals’ heads,

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and its possible this definition of
language, or our ways of measuring it,

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don’t apply to them.

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But as far as we know, only humans 
have language.

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And while humans speak around 
7,000 distinct languages,

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any child can learn any language,

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indicating that the biological machinery
underlying language

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is common to all of us.

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So what does language mean for humanity?

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What does it allow us to do, 
and how did we come to have it?

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Exactly when we acquired this capacity
is still an open question.

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Chimps and bonobos are our closest
living relatives,

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but the lineage leading to humans 
split from the other great apes

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more than four million years ago.

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In between, there were many species—
all of them now extinct,

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which makes it very difficult to know
if they had language or anything like it.

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Great apes give one potential clue 
to the origins of language, though:

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it may have started as gesture rather
than speech.

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Great apes gesture to each other in the
wild much more freely than they vocalize.

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Language may have begun to take shape
during the Pleistocene,

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2-3 million years ago, with the emergence
of the genus Homo

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that eventually gave rise 
to our own species, homo sapiens.

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Brain size tripled, and bipedalism freed
the hands for communication.

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There may have been a transition from
gestural communication

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to gestural language—from pointing 
to objects and pantomiming actions

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to more efficient, abstract signing.

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The abstraction of gestural communication
would have removed the need for visuals,

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setting the stage for a transition 
to spoken language.

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That transition would have likely 
come later, though.

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Articulate speech depends on a vocal tract
of a particular shape.

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Even our closest ancestors, the 
Neanderthals and Denisovans,

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had vocal tracts that were not optimal,

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though they likely had some 
vocal capacity,

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and possibly even language.

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Only in humans is the vocal tract optimal.

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Spoken words free the hands for activities
such as tool use and transport.

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So it may have been the
emergence of speech,

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not of language itself, that led to the 
dominance of our species.

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Language is so intimately tied to complex
thought, perception, and motor functions

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that it’s difficult to untangle
its biological origins.

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Some of the biggest mysteries remain:

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to what extent did language as a 
capacity shape humanity,

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and to what extent did humanity shape
language?

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Did the vast number of scenarios we can 
envisage

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come before our ability to share them,
or did they evolve in concert?