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In the Shadow
of Man
Jane van Lawick-Goodall
The amazing success of humans as a species is the result of
the evolutionary development of our brains which has led,
among other things, to tool-using, tool-making, the ability
to solve problems by logical reasoning, thoughtful cooperation,
and language. One of the most striking ways in which chimpanzees
biologically resemble humans lies in the structure of their
brains. The chimpanzee, with the capacity for primitive reasoning,
exhibits a type of intelligence more like that of humans than
does any other mammal living today. The brain of the modern
chimpanzee is probably not too dissimilar to the brain that
so many millions of years ago directed the behavior of the
first ape man.
For a long time, the fact that prehistoric
people made tools was considered to be one of the major criteria
distinguishing them from other creatures. As I pointed out
earlier, I have watched chimpanzees modify grass stems in
order to use them to probe for termites. It is true that the
chimpanzee does not fashion tools to "a regular and set
pattern"—but
then, prehistoric people, before their development of stone
tools, undoubtedly poke around with sticks and straws, at
which stage it seems unlikely that they made tools to a set
pattern either.
It is because of the close association in
most people's minds of tools with humans that special attention
has always been focused upon any animal able to use an object
as a tool; but it is important to realize that this ability,
on its own, does not necessarily indicate any special intelligence
in the creature concerned. The fact that the Galapagos woodpecker
finch uses a cactus spine or twig to probe insects from crevices
in the bark is indeed a fascinating phenomenon, but it does
not make the bird more intelligent than a genuine woodpecker
that uses its long beak and tongue for the same purpose.
The point at which tool-using and tool-making,
as such, acquire evolutionary significance is surely when
an animal can adapt its ability to manipulate objects to a
wide variety of purposes, and when it can use an object spontaneously
to solve a brand-new problem that without the use of a tool
would prove insoluble.
At the Gombe Stream alone we have seen chimpanzees
use objects for many different purposes. They use stems and
sticks to capture and eat insects and, if the material picked
is not suitable then it is modified. They use leaves to sop
up water they cannot reach with their lips—and first they
chew on the leaves and thus increase their absorbency. We
have seen them use handfuls of leaves to wipe dirt from their
bodies or dab at wounds.
In captivity chimpanzees often use objects
as tools quite spontaneously. One group that was studied intensively
by Wolfgang Kohler used sticks to try to pry open box lids
and dig in the ground for roots. They wiped themselves with
leaves or straw, scratched themselves with stones and poked
straws into columns of ants in order to eat the insects much
like the Gombe Stream chimpanzees probe for termites. They
often used sticks and stones as weapons during aggressive
encounters. Extensive tests have been carried out in laboratory
settings in order to find out more about the tool-making ability
of chimpanzees.
Results show that they can pile up to five
boxes one on top of the other in order to climb to hanging
food, that they can fit up to three tubes together to reach
food placed outside the bars of their cages, and that they
can unwind part of a length of wire for the same purpose.
So far, however, no chimpanzee has succeeded in using one
tool to make another. Even with teaching, one chimpanzee,
the subject of exhaustive tests, was not able to use a stone
hand ax to break a piece of wood into splinters suitable for
obtaining food from a narrow pipe. She could do this when
the material was suitable for her to break off pieces with
her teeth but, although she was shown how to use the hand
ax on tougher wood many times, she never even attempted to
make use of it when trying to solve the problem. However,
many other chimpanzees must be tested before we say that the
chimpanzee as a species is unable to perform this act. Some
humans are mathematicians—others are not.
When the performance of chimpanzees in the
field is compared with their actual abilities in test situations,
it would seem that, in time, they might develop a more sophisticated
tool-culture. After all, primitive people continued to use
their early stone tools for thousands of years, virtually
without change. Then we find a more sophisticated type of
stone tool-culture suddenly appearing widespread across the
continents. Possibly stone-age genius invented the new culture
and others, who undoubtedly learned from and imitated each
other, copied the new technique.
If chimpanzees are allowed to continue loving,
they, too, might suddenly produce a race of chimp superbrains
and evolve and entirely new culture. For it seems almost certain
that, although the ability to manipulate objects is innate
in a chimpanzee, the actual tool-using patterns practiced
by the Gombe Stream chimpanzees are learned by the infants
from their elders. We saw one very good example of this. It
happened when a female had diarrhea: she picked a large handful
of leaves and wiped her messy bottom. Her two-year-old infant
watched her closely and then twice picked leaves and wiped
his own clean bottom.
To Hugo and me, and assuredly to many scientists
interested in human behavior and evolution, one significant
aspect of chimpanzee behavior lies in the close similarity
of many of their communicatory gestures and postures to those
of humans. Not only are the actual positions and movements
similar to our own but also the contexts in which they often
occur.
When a chimpanzee is suddenly frightened,
it frequently reaches to touch or embrace a chimpanzee nearby,
much like a child watching a horror film may seize a companion's
hand. Both chimpanzees and humans seem reassured in stressful
situations by physical contact with another individual. Once
David Graybeard caught sight of his reflection in a mirror.
Terrified, he seized Fifi, then only three years old. Even
such contact with a very small chimp appeared to reassure
him; gradually he relaxed and the grin of fear left his face.
Humans may sometimes feel reassured by holding or stroking
a dog or some other pet in moments of emotional crisis.
This comfort, which chimpanzees and humans
alike appear to derive from physical contact with each other,
probably originates during the years of infancy, when for
so long the touch of the mother, or the contact with her body,
serves to calm the frights and soothe the anxieties of both
ape and human infants. So, when the child grows older and
its mother is not always close at hand, it seeks the next
best thing—close physical contact with another individual.
If its mother is around, however, it may deliberately pick
her out as its comforter. Once when Figan was about eight
years old he was threatened by Mike. He screamed loudly and
hurried past six or seven other chimps nearby until he reached
Flo: then he held his hand toward her and she held it with
hers. Calmed, Figan stopped screaming almost at once. Young
human beings, too, continue to unburden their hearts to their
mothers long after the days of childhood have passed—provided,
of course, that an affectionate relationship exists between
them.
When chimpanzees are overjoyed by the sight
of a large pile of bananas they pat and kiss and embrace one
another as two friends might embrace when they hear good news,
or as a child may leap to hug its mother when told of a special
treat. We all know those feelings of intense excitement or
happiness which cause people to shout and leap around, or
to burst into tears. It is not surprising that chimpanzees,
if they feel anything like this, should seek to calm themselves
by embracing their companions.
Chimpanzees, after being threatened or attacked
by a superior, may follow the aggressor, screaming and crouching
to the ground or holding out their hands. They are, in fact,
begging a reassuring touch from the other. Sometimes they
will not relax until they have been touched or patted, kissed
or embraced. Figan several times flew into a tantrum when
such contact was withheld, hurling himself about on the ground,
his screams cramping in his throat until the aggressor finally
calmed him with a touch. I have seen a human child behaving
in the same sort of way, hollowing his mother around the house
after she has told him off, crying, holding on to her skirt,
until finally she picked him up and kissed and cuddled him
in forgiveness. A kiss or embrace or some other gesture of
endearment is an almost inevitable outcome once a matrimonial
disagreement has been resolved, and in many cultures the clasping
of hands occurs to demonstrate renewal of friendship and forgiveness
after a quarrel.
When one human begs forgiveness from or gives
forgiveness to another there are, however, moral issues involved;
it is when we consider these that we get into difficulties
in trying to draw parallels between chimpanzees and human
behavior. In chimpanzee society, the principle involved ,when
a subordinate seeks reassurance from a superior, or when a
high-ranking individual calms another, is in no way concerned
with the right or wrong of an aggressive act. A female who
is attacked for no reason other than she happens to be standing
too close to a charging male is quite as likely to approach
the male and beg a reassuring touch as is the female who is
bowled over by a male while she attempts to take a fruit from
his pile of bananas.
Again, while we may make a direct comparison
between the effect on an anxious chimpanzee or human of a
touch or embrace of reassurance, the issue becomes complicated
if we probe into the motivation that directs the gesture of
the ape or the human who is doing the reassuring. Human beings
are capable of acting from purely unselfish motives; we can
be genuinely sorry for others and try to share in their troubles
in an effort to offer comfort. It is unlikely that a chimpanzee
acts from feeling quite like these; I doubt whether even members
of one family, united as they are by strong mutual affections,
are ever motivated by pure altruism in their dealings with
one another.
On the other hand, there may be parallels
in some instances. Most of us have experienced sensations
of extreme discomfort and unease in the presence of
abject, weeping person. We may feel compelled to try to calm
the person, not because we feel compassion in the altruistic
sense, but because the behavior disturbs our own feeling of
well-being. Perhaps the sight—and especially the sound—of
a crouching, screaming subordinate similarly makes a chimpanzee
uneasy; the most efficient way of changing the situation is
to calm the other with a touch.
Another area of similarity between chimpanzees
and humans is greeting behavior. When two chimpanzees greet
each other after a separation, their behavior often looks
amazingly like that shown by two humans in the same context.
Chimpanzees may bow or crouch to the ground, hold hands, kiss,
embrace, touch, or pat each other on almost any part of the
body, especially the head and face. A male may chuck a female
of an infant under the chin. Humans in many cultures, show
one or more of these gestures.
In human societies much greeting behavior
has become ritualized. People who smile when greeting a friend,
or who incline their heads when passing an acquaintance in
the street, are not necessarily acknowledging that the other
has a superior social status. Yet the nod undoubtedly derives
from submissive bowing or prostration and the smile from a
status of the individuals concerned, particularly on formal
occasions.
A greeting between two chimpanzees nearly
always serve such a purpose—it reestablishes the dominance
status of the one relative to the other. When nervous Olly
greets Mike she may hold out her hand toward him, or bow to
the ground, crouching submissively with downbent head. She
is, in effect, acknowledging Mike's superior rank. Mike may
touch or pat or hold her hand, or touch her head, in response
to her submission. A greeting between two chimps is usually
more demonstrative when the individuals concerned are close
friends, particularly when they have been separated for days
rather than hours. Goliath often used to fling his arms around
David, and the two would press their lips to each other's
faces or necks when they met; whereas a greeting between Goliath
and Mr. Worzle seldom involved more than a casual touch even
when the two had not seen each other for some time.
If we survey the whole range of the communication
signals of chimpanzees on the one hand and humans on the other,
we find striking similarities in many instances. It would
appear, then, that human and chimp either have evolved gestures
and postures along a most remarkable parallel or that we share
with the chimpanzees an ancestor in the dim and very distant
past; an ancestor, moreover, who communicated by means of
kissing and embracing, touching and patting and holding
hands.
One
of the major differences between humans and our closest living
relative is, of course, that the chimpanzee has not developed
the power of speech. Even the most intensive efforts to teach
young chimps to talk have met with almost no success. Verbal
language represents a truly gigantic step forward in human
evolution.
Chimpanzees do have a wide range of calls,
and these certainly serve to convey some types of information.
When a chimp finds good food it utters loud barks; other chimps
in the vicinity instantly become aware of the food source
and hurry to join in. An attacked chimpanzee screams and this
may alert its mother or a friend, either of whom may hurry
to its aid. A chimpanzee confronted with an alarming and potentially
dangerous situation utters a spine-chilling wraaaa—again,
other chimps may hurry to the spot to see what is happening.
A male chimpanzee, about to enter a valley or charge toward
a food source, utters his pant-hoots—and other individuals
realize that another member of the group is arriving and can
identify which one. To our human ears each chimpanzee is characterized
more by its pant-hoots than by any other type of call. This
is significant since the pant-hoot in particular is the call
that serves to maintain contact between the separated groups
of the community. Yet the chimps themselves can certainly
recognize individuals by other calls; for instance, a mother
knows the scream of her offspring. Probably a chimpanzee can
recognize the calls of most of its acquaintances.
While chimpanzee calls do serve to convey
basic information about some situations and individuals, they
cannot for the most part be compared to a spoken language.
Humans by means of words can communicate abstract ideas; they
can benefit from the experiences of others without having
to be present at the time; they can make intelligent cooperative
plans.
Recently it has been proved that the chimpanzee
is capable of communicating with people in quite a sophisticated
manner. There are two scientists in America, R. Allen and
Beatrice Gardner, who have trained a young chimpanzee in the
use of the approved sign language of the deaf. The Gardners
felt that, since gesture and posture formed such a significant
aspect of chimpanzee communication patterns, such a sign language
might be more appropriate than trying to teach vocal words.
Washoe was brought up from infancy constantly
surrounded by human companions. These people from the start
communicated in sign language with Washoe and also with each
other when in the chimp's presence. The only sounds they made
were those approximating chimpanzee calls such as laughter,
exclamations, and imitations of Washoe's own sounds.
Their experiment has been amazingly successful.
At five years of age Washoe can understand some three hundred
and fifty different symbols, many of which signify clusters
of words rather than just a single word, and she can also
use about one hundred and fifty of them correctly.
I have not seen Washoe; but I have seen some
film demonstrating her level of performance and， strangely
enough, I was most impressed by an error she made. She was
required to name, one after the other, a series of objects
as they were drawn from a sack. She signed off the correct
names very fast—but even so, it could be argued that an
intelligent dog would ultimately learn to associate the sight
of a bowl with a correct response. And then a brush was shown
to Washoe, and she made the sign for a comb. That to me was
very significant. It is the sort of mistake a small child
might make, calling a shoe a slipper or a plate a saucer—but
never calling a shoe a plate.
Perhaps one of the Gardners' most fascinating
observations concerns the occasion when for the first time
Washoe was asked (in sign language) "Who is that?" as she
was looking into a mirror. Washoe, who was very familiar with
mirrors by that time, signaled back, "Me, Washoe."
This is, in a way, a scientific proof of a
fact we have long known—that, in some way, the chimpanzee
has a primitive awareness of Self. Undoubtedly there are people
who would prefer not to believe this, since even more firmly
rooted than the old idea that humans alone are the only tool-making
beings is the concept that humans alone in the animal kingdom
are Self-conscious. Yet, this should not be disturbing. It
has come to me, quite recently, that it is only through a
real understanding of the ways in which chimpanzees and humans
show similarities in behavior that we can reflect with meaning
on the ways in which humans and chimpanzees differ. And only
then can we really begin to appreciate, in a biological and
spiritual manner, the full extent of our uniqueness.
Yes, human beings definitely
overshadow the chimpanzee. The chimpanzee is, nevertheless,
a creature of immense significance to the understanding of
humans. Just as they are overshadowed by us, so the chimpanzees
overshadow all other animals. They have the ability to solve
quite complex problems, they can use and make tools for a
variety of purposes, their social structure and methods of
communication with each other are elaborate, and they show
the beginnings of Self-awareness. Who knows what the chimpanzees
will be like forty million years hence? It should be of concern
to us all that we permit them to live, that we at least give
them the chance to evolve.
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