http://www.mc.maricopa.edu/dept/d10/asb/learning/origins/optional3.html

(This first segment has been taken from Carl Sagan and Ann Druyan's
Shadows of Forgotten Ancestors while the second segment has been taken
from Richard Leakey's new book Origin's Reconsidered.)

SEGMENT ONE 

(Pages 391-399) 

Although many chimps literally do not know enough to come in out of
the rain, they're able to use tools. Not only that: they're able to
premeditate the use of tools-to acquire a tool now for some action
they intend to perform later. They go large distances to find the
right kind of stone or stick, and then lug it home. They seem to have
had its ultimate use in mind all the while.

"It has often been said," wrote Darwin in The Descent of Man, "that an
animal uses any tool; but the chimpanzee in a state of nature cracks
native fruit, somewhat like a walnut, with a stone." His source was
that acute but easily offended Victorian observer of chimps, Thomas
Savage, M.D. Chimpanzees regularly crack open hard-shell seeds and
nuts with a stone hammer against a stone or wooden anvil; and they'll
carry the appropriate rocks over a good fraction of a kilometer for
the purpose. At other times, wooden clubs may be used as
nutcrackers. In the Tai Forest in the Ivory Coast, chimps select an
appropriate club, climb a cola tree, pick the choice cola nuts, and
crack them open using the branch as the anvil and the club as the
hammer. Female chimps are more likely to employ hammer-and-anvil
technology than males, and they're better at it. {Similar examples
occur in other species. The playful and intelligent sea otter
regularly dives to the ocean floor, retrieves hard-shelled mussels and
an appropriate stone, swims to the surface, floats on its back, and
then cracks open the mussels using the tone as an anvil. Some birds
drop bivalves on rocks to crack them open. Egyptian vultures and
black-breasted buzzards drop stones from altitude on the large eggs of
emus and ostriches in order to dine on the contents. In an apocryphal
story, the ancient Greek playwright Aeschylus is said to have been
killed when a vulture (or eagle)cropped a heavy stone (or a turtle . .
. accounts differ) on his bald head, which it perhaps mistook for the
egg of a flightless bird.}

A chimp breaks off a long grass stalk or a reed so she may use it
later, hundreds of meters away, more than an hour in the future, to
lure delectable termites out of a log or termite mound. She must
remove superfluous leaves and twigs, shape it, shorten it, insert it
into the termite tunnel with a deft twisting motion to follow the
interior contours, shake it seductively to attract termites onto it,
and then with great care remove it without scraping off too
many. Chimps take years to perfect their technique and routinely teach
it to their young, who are avid pupils. This exactly satisfies one
confident definition of "the uniqueness of man's toolmaking"-namely,
"the fashioning, out of natural materials, of an implement designed to
be used at a distant time and on objects not now perceptually
present."

How difficult is chimpanzee termite fishing? What depth of intellect
and manual dexterity are required? Suppose you are dropped naked into
the Gombe Preserve in Tanzania and, like it or not, discover that
termites are your principal hedge against malnutrition or
starvation. You know they're an excellent source of protein; you know
that self-respecting humans in many parts of the world regularly eat
them. You manage to put aside whatever compunctions you may feel. But
catching them one at a time is not going to be worth the
effort. Unless you're lucky enough to encounter them when they're
swarming, you're going to have to make a tool, repeatedly insert it
into their meter-high mound, introduce the tool into your mouth, and
strip off the clinging termites with your teeth and lips as you
withdraw the tool from your mouth. Could you do as well as a chimp?

The anthropologist Geza Teleki tried to find out. He spent months in
Gombe under the tutelage of a chimp named Leakey, who was adept at the
technique. Teleki wrote about his findings in a famous scientific
paper called "Chimpanzee Subsistence Technology.'' The Gombe termites
mainly come out at night; before dawn they expertly wall up all the
entrances to their mounds. Chimps routinely begin their termite
foraging by scraping away these entrance barriers. Teleki's inquiry
started there:

Having repeatedly observed [chimpanzee] individuals approach a mound,
make a rapid visual scan of the surface while standing on or beside
it, and reach decisively out-with a high degree of predictive
accuracy-to uncover a tunnel, I was soon impressed by the apparent
ease with which tunnels could be located. In attempting to learn the
technique, I applied several experimental procedures: examining in
minute detail all crack patterns, protuberances, depressions and other
"topographic" features in the clay. But, after weeks of futile
searching for the essential clue, I had to resort to scraping mound
surfaces with a jackknife until a tunnel was inadvertently exposed. My
inability to find any physical features which could serve as visual
clues eventually led me to realize that chimpanzees may possess
knowledge far beyond my expectations.. . .

The only hypothesis which, at this point, seems to reasonably account
for the observed facts is that an adult chimpanzee may know
(memorize?) the precise location of two or more tunnels in the most
familiar mounds. Moreover, since intensive probing is restricted to a
short annual season, the possibility that chimpanzees retain a mental
map of core mound features during the intervening months must also be
considered. That chimpanzees require a prolonged learning period
(i.e. 4-5 years) to gain proficiency in this technique . . ., and that
some individuals are known to have the capability to retain specific
information for many years, provides circumstantial support for this
hypothesis.

Next, Teleki looked into a selection of raw materials for the
manufacture of the termite probe:

When performed by experienced chimpanzees, the selection procedure
seems deceptively simple. After a brief visual scan of the nearby
vegetation, a chimpanzee will usually extend a hand and deftly tear
off a twig, vine or grass stalk. Sometimes the individual must move a
few paces away from the mound and fetch a suitable probe, and in some
cases 2-3 objects are initially selected. These may be rapidly
examined and discarded until some specification is met in one, or
several may be carried to the mound for subsequent selection. Whenever
it occurs, the selection is made in a swift, almost casual manner, and
modification is begun if necessary. Without being aware of the nuances
involved, it is easy to undervalue the proficiency needed to perform
these maneuvers.

Chimpanzees presumably have the experience whereby the properties of
an object can be evaluated before it is applied to the task of
probing, for the rate of error in selecting probes is not
high. . . When probing for termites, the specifications are in fact
surprisingly stringent: if the vine or grass selected is too pliant,
it will buckle and collapse (accordion-like when inserted into a
twisted tunnel; if, on the other hand, the object is too stiff or
brittle, it will catch on the tunnel walls and either break or resist
entry to the necessary depth....

Despite months of observing and aping adult chimpanzees as they
selected probes with enviable ease, speed and accuracy, I was unable
to achieve their level of competence. Similar ineptness can only be
observed in chimpanzees below the age of about 4-5 years.

Finally, putting aside the difficulties in finding the tunnel
entrances and manufacturing the tools, Teleki set himself to learning
how to use a competently produced tool:

I spent many hours inserting probes, pausing for the designated
interval, and pulling them out again-without getting any
termites. Only after some weeks of nearly total failure . . . did I
finally begin to grasp the problems involved . . .In order to collect
these subterranean termites, the probing object must first be
carefully and dexterously inserted to a depth of about 8-16 cm
[centimeters], with appropriate turns of the wrist so that the object
navigates the twisting channel. The probe must then be gently vibrated
with the fingers during the prescribed pause, for without this
movement the termites may not be stimulated into biting firmly onto
the probe. However, if the vibration is performed too lengthily or
roughly, there is an excellent chance that the probe will be cut
through by the [termites'] mandibles while still in the tunnel. When
these preliminary actions have been correctly performed, the probe,
presumably with dozens of termites now attached, must be extracted
from the tunnel. Once again there are nuances to be observed. If the
object is too rapidly or clumsily pulled out, the insects are likely
to be scraped off along the sides of the tunnel, which then yields
nothing but a shredded probe. The hand motions must be reasonably but
not overly swift and, once started, uniformly fluid and graceful. If
the tunnel is particularly tortuous (a feature which can be determined
during insertion of the probe), the success of the catch can be
ensured by a slow twisting of the wrist while the probe is pulled out.

It is a little daunting to discover-on the very technological grounds
on which human superiority is often claimed-that after months of
apprenticeship, human scientists cannot do as well as preadolescent
chimps. Teleki remained generous and good-natured about his
failure. In the acknowledgments at the end of the paper, among thanks
to various organizations for financial and logistical support, there
appears this sentence: "I am, in addition, more than grateful to the
patient and tolerant Leakey, whose termite-collecting skills so
out-stripped mine."

The chimp style of teaching nut cracking and termite fishing to the
young is relaxed-by example and not by rote. The student fiddles with
the tools and tries out various approaches, rather than slavishly
copying every hand movement of the instructor. Gradually the technique
improves. Chimps have for this reason been criticized as not really
having culture. (Ironically, one group of scientists denies chimps
language because-as we described earlier-they are said to be too
imitative, while another group of scientists denies chimps culture
because they are said to be not imitative enough.)

The learning style of the great physicist Enrico Fermi was to ask
colleagues to state the problems they had recently solved, but to
withhold their answers: He could understand the problem only by
working it through himself. Learning by doing is-in science and
technology, as in many other human activities-much more effective than
learning by rote. Knowing, as the chimps do, that a problem exists and
can be solved with the tools at hand is most of the battle.

Baboons in Gombe eat termites, but almost entirely during the two or
three-week period in which the insects migrate. Then the baboons can
be seen gathering and slurping the insects, and leaping into the air
to catch them on the wing. In less bountiful times, baboons will be
shooed away from a termite mound by an arriving group of
chimpanzees. Sometimes the displaced baboons sit a little distance
away, morosely observing the chimps working away with their tools on
the mound. When the chimps are done, they leave their modified stalks
and reeds at the base of the mound. But no baboon has ever been
observed trying to use an abandoned tool-even though it could extend
their termite season from weeks to months. Apparently the baboons just
don't have it in them. They're not smart enough. Probably their brains
are too small.

As chimps are much better than baboons at collecting termites, so some
pre industrial humans who routinely eat termites are much better than
chimps. They dig open the termite mounds, or fumigate them, or flood
them with water. One of the more elegant practices is -with the tongue
on the palate, or two pieces of wood gently touched to the mound's
surface- to imitate the sound of raindrops, which entices the termites
out of their nest. Chimps have never been observed to use these
techniques. Probably they're not smart enough. Probably their brains
are too small.

What we find most interesting is the overlap. Some chimps lack even
probe technology, and are no better at catching termites than baboons
are. Other chimps are armed with a well-developed if rudimentary
technology, many steps having to be done correctly and in the right
sequence for the method to work-as good as many human cultures,
although nowhere near as good as some. There are human cultures barely
up to the highest chimpanzee standards of termite catching, and others
only on a par with the baboons. No sharp boundaries are apparent here
separating baboons from chimps, or chimps from humans.

Chimps also drop branches on intruders and sop up drinking water with
leaves. While they cannot be described as fastidious or obsessively
hygienic, chimps are known to use leaves as toilet paper and
handkerchiefs, and twigs as toothbrushes. They employ sticks for
digging up roots, for investigating animals in burrows and knotholes,
and -like a croupier at a gaming table-for raking in otherwise
inaccessible fruit. If they were able to manufacture more complex
tools, they certainly would have the intelligence and dexterity to use
them: In zoos, chimps try to steal the keys from the keeper's
pocket. When successful, they often manage to open the lock. Like us,
they can sometimes use their intelligence to escape from bondage.

Male chimps like to throw missiles-whatever is handy, generally sticks
and stones. (Like the inmates of college fraternity houses, they also
occasionally throw food.) Females are much less interested in
missiles. Chimps would throw stones at the visitors who gawk at them
in the traditional kind of zoo-if they had stones. As it is, all they
have is feces. When wild chimps are presented with a fairly realistic
mechanical leopard, after a reassurance frenzy of screams, hugs, and
mutual mountings, they find appropriate clubs and beat the effigy to
death-or at least until they knock the stuffing out. Or they'll pelt
it with stones. (In the same circumstance, baboons will furiously
attack the leopard, but without a thought of using clubs. Baboons just
don't know about tools.)

Chimps have stunned or killed by throwing stones. The directionality
of their throwing is good. Where they're deficient is in range: In
tense confrontations with prey or hostile peers, thrown rocks hit
their targets only a few percent of the time. Adolescent boys don't do
much better under comparable conditions. But even when inaccurate, a
hail of stones can be off-putting.

A distinction needs to be made between tool using and tool
making. Many scientists have conceded tool use to other animals, and,
following Benjamin Franklin, defined humans as the sole toolmaking
animal; where tools are manufactured, it is suggested, language cannot
be far behind. But the chimpanzee termite fishery industry makes it
clear that chimps, with considerable forethought, both make and use
tools. Chimps also have a rudimentary stone technology, although, as
far as we know, they don't manufacture stone tools in the wild. In
captivity, though, Kanzi-the linguistically talented bonobo-has,
imitating human models, hit stones together to produce sharp flakes,
which he then uses to cut a string so he can open a box which is
filled with food. (This is a causality sequence at least five steps
long.) As long as it's sharp enough to cut the string, Kanzi will
generally settle for the first crude stone knife he flakes off. But
the thicker the rope he must cut, the larger and sharper the knife he
makes.

Evidence of chimpanzee talent to combine objects purposefully to make
tools has actually been with us for decades:

Between 1913 and 1917, Wolfgang Kohler conducted observations and
experiments on the intelligence of chimpanzees at a field station in
North Africa. In one study a male chimpanzee, Sultan, was led into a
room where a banana had been tied to a string and suspended from the
ceiling in a corner. A large wooden box had also been placed in the
center of the room, open side up. Sultan first tried to reach the
fruit by jumping, but this quickly proved futile. He then "paced
restlessly Up and down, suddenly stood still in front of the box,
seized it, tipped it . . . straight towards the objective . . . began
to climb up it . . . and springing upwards with all his force, tore
down the banana." A few days later Sultan was taken into a room with a
much higher ceiling, where again there was a suspended banana, as well
as a wooden box and a stick. After failing to get the banana with the
stick alone, Sultan sat down "with an air of fatigue . . . gazed about
him, and scratched his head." He then stared at the boxes, suddenly
leaped up, seized a box and a stick, pushed the box underneath the
banana, reached up with the stick and knocked the fruit down. Kohler
was struck with the apparently thoughtful period that preceded
Sultan's solution, as well as with his sudden and directed
performance. Such "insightful" behavior apparently contrasted with
other forms of learning, which develop gradually and depend on
reinforcement.

It's not hard to imagine an especially insightful chimp or bonobo
wondering if there weren't some way to make a stone flake cut better
or a projectile go farther.

Since the progress of human technology is a continuum, to pick a
particular milestone-the domestication of fire, say, or the invention
of the bow and arrow, agriculture, canals, metallurgy, cities, books,
steam, electricity, nuclear weapons, or spaceflight-as the criterion
of our humanity would be not just arbitrary, but would exclude from
humanity every one of our ancestors who lived before the selected
invention or discovery was made. There is no particular technology
that makes us human; at best it could only be technology in general,
or a propensity for technology. But that we share with others.

Like us, nonhuman primates are not all the same. They vary in focus
from individual to individual and group to group. Some, like Imo, are
technological geniuses. Others, like the hierarchy-besotted macaque
males, are hopelessly old-fashioned and stuck in their ways. One chimp
population pounds nuts, another does not. Some probe for termites,
others only for ants. Some use grass stalks and vines to coax the
insects out, others sticks and twigs. Females preferentially use
hammers and anvils, males preferentially throw stones. None of them,
so far as we know, has ever used a stick to dig out a nutritious root
or tuber, although it ought to be possible and adaptive. Some
individuals find technology uncongenial or intellectually too taxing
and never use it, despite the obvious advantages accruing to other
members of their group who are comfortable with technology. Some large
groups have no technology at all. "I'm embarrassed to say," says an
observer of a community of Ugandan chimps, "that the Kibale
chimpanzees appear as the country bumpkins of the chimp world." He
goes on to speculate that life is too easy and food too plentiful at
Kibale for the challenge of deprivation to elicit the response of
technology...