a hairy back!" was Lily Tomlin's candidate for the first
human sentence. But whatever the content of that original remark,
if Michael C. Corballis is correct, it was expressed in gestures,
Mr. Corballis, a psychologist at the University of Auckland, in
New Zealand, is the latest proponent of a controversial idea known
among language experts as the "gestural theory." In
essence, gestural theorists contend that long before early humans
spoke they jabbered away with their hands.
Where language comes from remains one of human evolution's
enduring puzzles. But in a new book, "From Hand to Mouth: The
Origins of Language" (Princeton Univerity Press), Mr.
Corballis pluckily takes a stand, arguing that speech was an
ingenious innovation but not quite the freakish marvel that
linguists have often made it out to be. Proposing that human
ancestors made the switch from gestures to speech quite recently
he puts the date at around 50,000 years ago, a mere yesterday
in evolutionary terms Mr. Corballis believes that language
itself, and the sophisticated mental capacities necessary to
produce it, are far older.
"The common ancestor of five or six million years ago
would have been utterly incapable of a telephone conversation but
would have been able to make voluntary movements of the hands and
face that could at least serve as a platform upon which to build a
language," he writes. "Grammatical language may well
have begun to emerge around two million years ago but would at
first have been primarily gestural, though no doubt punctuated
with grunts and other vocal cries that were at first largely
involuntary and emotional."
It sounds plausible enough. All you have to do is look around
to see how much hand-waving still accompanies human communication
today even people on cell phones do it. But Mr. Corballis has
yet to convince many linguists of the theory's merits.
"He's not a linguist, and I think he doesn't appreciate
the sophistication of grammatical organization," said Ray
Jackendoff, a professor of linguistics at Brandeis University.
"I never saw any reason one way or the other to say that
language started gesturally rather than vocally. If it started in
the gestural modality, you still have to explain how in switching
to that vocal modality there's this terrific adaptation."
Here, of course, the fossil record is of little help. As Mr.
Jackendoff put it: "The problem of talking about the
evolution of language in any detail is that there is no evidence.
It's pure speculation."
But that hasn't stopped scholars from pursuing all manner of
theories or engaging in charged debate. In 1866, the
Linguistic Society of Paris banned all discussion of the evolution
of language presumably in order to keep tempers in check. A
few years later, Charles Darwin ventured that human speech may
have evolved from animal cries, a notion that was famously derided
by his opponents as the "bow-wow" theory. The French
philosopher Abbι Ιtienne de Condillac, whom Mr. Corballis
credits with being the first gestural theorist, took a more
strategic tack: when he presented his theory in 1746, he delivered
it in the form of a fable so as not to arouse the ire of the
Catholic Church. (In those days, the official wisdom was that
language came from God.)
In recent decades, resistance to the origins question has come
less from clerics than from cutting-edge linguists and biologists.
For example, Noam Chomsky, the M.I.T. professor whose ideas have
dominated the field for more than 40 years, has often been accused
of depicting language as a trait so remarkable that natural
selection is virtually helpless to explain it.
Mr. Chomsky's celebrated theory of Universal Grammar supposes
that human languages share an underlying set of rules that are
innate rather than learned. But some readers of his work have
taken him to mean that the capacity for language arose all at once
rather than incrementally, the product of what one critic
derisively termed "the cognitive equivalent to the Big
Lately, however, Darwinian accounts of language have begun to
proliferate, buoyed by new research on primate communication and
human sign language as well as the more general scholarly vogue
for evolutionary theory. In his 1994 best seller, "The
Language Instinct," the M.I.T. professor Steven Pinker
eloquently defended the idea that language evolved by natural
selection, though he conceded that "the first steps toward
language are a mystery." (If forced to speculate, he added,
he would be inclined to bet on primate calls rather than gestures
as a likely precurser to speech.)
Mr. Pinker's book seems to have opened a floodgate of
possibilities. In 1996, the British anthropologist Robin Dunbar
proposed that language had evolved from primate grooming behavior.
Among apes and monkeys, physical contact tickling, scratching
and picking at each other's lice functions as social glue,
establishing hierarchies and alliances and communicating empathy
or remorse. But back-scratching a whole band of baboons takes
time. As early hominid populations expanded, Mr. Dunbar theorizes,
speech simply became the more efficient option think of it as
a kind of group massage.
More recently, Peter MacNeilage and Barbara Davis, researchers
at the University of Texas at Austin, have developed an "ingestive
theory," which links the evolution of speech to the movements
the mouth makes while chewing. "The mouth closes and opens in
chewing just as it closes for consonants and opens for
vowels," Mr. MacNeilage explained in a telephone interview.
Meanwhile, Michael Arbib, a computational neuroscientist at the
University of Southern California, is working on a variant of the
gestural theory based on the discovery of similarities in the way
human brains recognize language and monkey brains recognize
"The whole field is not settled," said William
Calvin, a neurobiologist at the University of Washington in
Seattle, whose own theory is that language evolved from the rapid
mental reflexes required to, say, throw a spear at a running
mammoth. "Everybody's got a theory."
Mr. Corballis says evidence to support the gestural theory is
growing. Researchers now know, for example, that sign languages
are as grammatically sophisticated as spoken ones. Moreover, both
speech and signing depend on the left side of the brain the
same side that happens to control most people's dominant hand, the
From an evolutionary standpoint, Mr. Corballis argues, the
gestural theory has several advantages. For one thing, it would
help explain why chimpanzees mankind's close cousins are
adept at learning forms of sign language and notorious failures
when it comes to imitating human speech or even controlling their
Moreover, he suggests, the upright posture adopted by early
hominids humans' apelike ancestors as long as two million
years ago would have facilitated hand-based communication. "Bipedalism
encouraged manual gesturing," Mr. Corballis said in a talk at
a recent Harvard University conference on language and evolution.
He hinted that gestural theory could clear up another mystery
about this period as well: why the stone tools of these early
hominids show little evolution for almost two million years,
despite increases in brain size. What if these bipedal creatures
were so caught up in five-fingered chit-chat that it got in the
way of their tool making? In the 1970's, one anthropologist went
so far as to suggest that the reason humans evolved unpigmented
palms unlike other primates is so their hand signals would
show up better around the campfire at night.
That leaves the sticky questions of why and when these
hypothetical skillful signers bothered to switch to speech. For a
while, Mr. Corballis speculates, they probably used a mix of both.
Then, about 50,000 years ago, there was a momentous change: an
explosion of technology, cave art, textiles and even musical
instruments. Mr. Corballis's interpretation? Freed from the task
of communicating, hominid hands were finally able to get down to
the real toil of creating civilization.
But his most provocative idea is that human ancestors stopped
gesturing and started talking not because their brains underwent a
sudden mutation a cognitive Big Bang but rather because it
seemed to some Homo sapiens at the time like a good idea. He
called the advent of autonomous speech a "cultural
invention," like writing, and one that "may have
occurred long after it became possible."
And once speech caught on, he argues, it gave Homo sapiens a
decisive advantage over less verbal rivals, including Homo erectus
and the Neanderthals, whose lines eventually died out. "We
talked them out of existence," Mr. Corballis said with a
The gestural theory makes for a captivating story. Yet like so
many other theories, it may turn out to be little more than that.
The question of where language comes from may simply be
unanswerable, said Richard Lewontin, a professor of biology at
Harvard. "If you don't have a closely related species with a
similar trait you have the problem of novelty," he said.
"And what you and I are doing right now, no bonobo or
chimpanzee will ever do.'`
Mr. Chomsky agreed. "This task intrigues people because
it's about us," he said. "But that doesn't make it a
scientific question. It may be important for us to know where we
came from, but if we can't answer that question scientifically, we
can't answer it. If you want to tell stories, well then, tell