Early Impression--What is Speech--First Efforts--The Phonograph--The
First Record of Monkey Speech--Monkey Words--Phonetics--Human Speech
and Monkey Speech
Among the blue hills and crystal waters of the Appalachian Mountains,
remote from the artificialities of the great cities, the conditions of
life under which I grew up were more primitive and less complex than
they are in the busy centers of vast population. There nature was the
earliest teacher of my childhood, and domestic animals were among my
first companions. Among such environments my youth was passed, and
among them I first conceived the idea that animals talk. As a child, I
believed that all animals of the same kind could understand each other,
and I recall many instances in which they really did so.
My elders said that animals could communicate with each other, but
denied that they could talk. As a boy, I could not forego the belief
that the sounds they used were speech; and I still ask: In what respect
are they not speech? This question leads us to ask another.
What is speech? Any oral sound, voluntarily made, for the purpose of
conveying a preconceived idea from the mind of the speaker to the
mind of another, is speech. Any oral sound so made and so discharging
this function in the animal economy is speech. It is true that the
vocabularies of animals, when compared with those of man, are very
limited; but the former are none the less real. The conception in the
mind of an animal may not be so vivid as it is in the human mind, but
the same conception is not always equally clear in two human minds. The
fact of its being vague does not lessen its reality.
Expression is the materialized form of thought, and speech is one mode
of expression. Every animal is capable of expressing any thought that
he is capable of conceiving, and such expression will be found to be
as distinct as the thought which it expresses. It is inconsistent with
every view of nature to suppose that any creature is endowed with the
faculty of thought and forbidden the means of expressing it.
It is true that there are some oral sounds which express emotion--such
as pain or pleasure. These may not properly be called speech, although
from them we may infer the state of mind attending them; but while they
are not truly speech, they appear to be the cytula from which speech
is developed. While emotions are not voluntary, they do not exist
apart from mind. They are produced by external causes, and the line of
demarcation which separates them from more definite forms of thought is
a vague and wavering one. Thought may be involuntary, but expression
arises from desire, and this is the sole motive of speech.
It is not the purpose of this work to discuss the problems of
psychology, except to state the grounds upon which we base the claim
that animals possess the faculty of speech; but this is intended as a
record of observed facts and from them the psychologist may make his
own deductions.
With the ever-present belief that animals could talk to each other, I
observed from year to year certain things which tended to confirm it.
About sixteen years ago an instance occurred which forever removed
from my mind all doubt or wavering. Prior to that time I had observed
that animals of the higher orders appeared to have the better types of
speech and, concurrent with this belief, I tabulated many facts. In
1884 I made a visit to the Cincinnati Zoölogical Garden, where I was
deeply impressed with the conduct of a school of monkeys occupying a
cage which also contained a large mandrill. This savage baboon was an
evident source of terror to the smaller inmates of the cage. A brick
wall separated the cage into two compartments. The one was intended
for summer and the other for winter occupancy. Through this wall was
a small doorway, large enough to admit the passage of the occupants.
I observed that two or three of the monkeys kept continual watch over
the conduct of the baboon and reported to the other monkeys every
movement that he made. When he was lying still, the monkeys passed back
and forth without fear, but the instant he rose to his feet or gave
any sign of disquiet the fact was promptly reported by the monkeys
on watch to those in the adjoining compartment, and they acted in
accordance with the warning. I was not able to determine the exact
thing they reported, but the nature of the report was evident, and I
resolved to learn more fully its meaning. After spending some hours
watching their conduct and listening to the sound which controlled it,
I became convinced that what they said was sufficiently definite to
guide the actions of those to whom it was addressed. In fact I should
have been willing to intrust my own safety to those warnings. After a
brief study of those sounds I was able to understand the attitude of
the baboon towards his neighbors; and while the warning contained no
elaborate detail that I could understand, the nature of his actions was
made evident. I observed that a certain sound of warning caused them
to act in a certain way, and a certain other sound caused them to act
differently.
From this start I determined to learn the speech of monkeys. I did not
suspect that the task would be so great as it has proved to be. I did
not foresee the difficulties that have since become apparent. Year
by year, as new ideas came to me, new barriers arose and the horizon
continually widened. Yet I was not discouraged at the poor success of
my first efforts. From time to time I visited the various collections
of monkeys in this country and even availed myself of those found with
traveling shows, hand organs, and elsewhere.
After some years of casual study it occurred to me that the phonograph
would be a great aid in solving this problem. It would enable me to
make more accurate comparisons of the sounds made by different monkeys;
and after duly considering the matter I went to Washington and made my
purpose known to Dr. Baker, of the Smithsonian Institution. This at
first evoked from him a smile, but after explaining the means by which
it was hoped to accomplish the end he looked upon the novel feat as a
new step in the science of speech.
Having secured a phonograph, I repaired to the animal house then
adjoining the Smithsonian Institution. At that time there were but two
live monkeys there, and these were the nucleus around which has grown
the present National Zoölogical Park at Washington. These two monkeys
were of different species, but had for some time occupied the same
cage. I had the female removed from the cage and carried into another
room. Then the phonograph was placed near her cage, and by various
means she was induced to utter a few sounds which were recorded upon
the wax cylinder. The machine was then placed near the cage containing
the male and the record repeated to him. His conduct plainly showed
that he recognized the sound and understood the nature of it. He
searched the horn from which the sounds proceeded and appeared to be
perplexed at not finding the monkey that had made them. He traced the
sound to its proper source, but, failing to find his mate, he thrust
his arm into the horn and felt around the sides of it in the vain hope
of finding her. The expression of his face was a study worthy of the
best efforts of the physiognomist.
Then a few sounds of his voice were recorded upon another cylinder and
were delivered to the female, who showed signs of recognition; but as
this record was very indistinct it did not evoke from her the interest
which the other had evoked from him.
This is doubtless the first instance in the history of speech that an
attempt was ever made to reduce the speech of monkeys to record. While
this first experiment was crude and the results were not conclusive, it
pointed in the right direction and it inspired to further efforts to
find the fountain head from which flows the great river of human speech.
Some critic at that time declared that this experiment could be of no
scientific value, because the monkey had been provoked to make the
sounds recorded, and the sounds so evoked were only sounds of anger or
profanity. It was not a matter of concern to me whether these words
were moral or profane, so long as they were speech sounds of a monkey
and were so recognized by other monkeys. If a monkey uses profanity, he
doubtless has some other forms of speech.
Shortly after this experiment I went to Chicago and made a record of a
brown _Cebus_ monkey. This record was of a sound most commonly used by
that species. I had no exact idea as to its meaning, but its frequent
use caused me to select it as one of their most important words. Having
secured this, I returned to New York. There I selected a monkey of the
same species and to him reproduced the record. He instantly gave signs
of understanding it and replied to it. Again and again this sound was
reproduced and he repeatedly answered it. He looked at the horn from
which it came, then at the moving instrument, and drew back from them.
But as the sound continued to proceed from the horn his interest seemed
to awaken. He approached the horn and cautiously peeped into it. The
sound was repeated. He thrust his arm into the horn and peeped around
the outside to see if he had scared the monkey out. Failing to find
him, he again retired from the horn, but responded to the sounds. He
appeared to regard the thing with a kind of superstition. He seemed
conscious of the fact that there should be a monkey there, but failing
to find it he evinced suspicion. I do not know to what extent he
regarded this as a spook, but he evidently realized that it was some
unusual thing.
In this experiment certain facts may be observed. The record delivered
to him nothing but the cold, mechanical sound. The elements of gesture,
etc., were entirely eliminated as factors in the problem, so that the
monkey had nothing to interpret except the sound. This would indicate
that the speech sound of a monkey as well as that of man carried
with it a fixed and constant meaning. This conclusion has since been
confirmed by ample and varied experiments with mechanical devices of
many kinds.
Among the defects observed in this experiment was the fact that I
had not provided a means of recording the sound made in reply to the
record. Subsequently I secured another instrument to do this. In
this manner I obtained a reply, and thus I had the two cylinders for
comparison. In like manner I repeated the experiment of delivering the
record with one machine and recording the reply with another, until
I had secured records of the speech sounds of nearly all the monkeys
in captivity in this country. Taking these records at my leisure, I
carefully compared and studied them, until I was able to interpret nine
sounds of the speech of the Capuchin monkeys, and, incidentally, a few
sounds of a great number of other species.
It is quite impossible to represent the sounds of monkey speech by
any literal formula, and it is difficult to translate them into their
exact equivalent of human speech; but, in order to convey some idea
of the nature and scope of that speech, I shall describe a word or
two. In the tongue of the brown Capuchin monkey the most important
word somewhat resembles the word “who,” uttered like “wh-oo-w.” The
phonetic effect is rich and musical. The vowel element which dominates
it is a pure vocal “u.” The radical meaning of this sound is food,
which is the central thought of every monkey’s life. It does not only
mean food in the concrete sense, referring to the thing to be eaten,
but it sometimes refers to the act of eating, in which sense it has
the character of a verb. At other times it refers to the desire to
eat or to the sensation of hunger, in which instance it may be said
to have the character of an adjective. But grammatical values depend
upon structure, and since the speech of monkeys is _monophrastic_ it
cannot truly be said to have grammatical form. All the sounds of this
species, so far as I have seen, are monosyllables; and most of them
contain but one distinct phonetic. I have therefore described them as
“monophonetic.” The word above described is sometimes used with the
apparent purpose of expressing friendship, or something of that kind.
Another word which refers to drink, or liquid, begins with a faint
guttural “ch,” gliding through a sound resembling the French diphthong
“eu,” and ending with a vanishing “y.” The sound is used with
reference to drink in much the same way as the other sound is used with
reference to food.
So far I have not found any trace of the vowels “a,” “e,” “i,” or “o,”
sounded long, but in one sound of alarm emitted under stress of great
fear or in case of assault, the vowel element resembles short “i.” This
sound is uttered in a pitch about two octaves above a human female
voice.
All of the sounds made by monkeys and, so far as I have observed, by
other animals, refer to their natural physical wants. They are not
capable of expressing intricate or abstract thoughts, for the animal
himself has no such thoughts. Their simple modes of life do not require
complex thoughts.
A striking point of resemblance between human speech and that of the
simian is found in a word that “Nellie” (one of my pets) used in
warning me of the approach of danger. It is not that sound elsewhere
described as the alarm sound used in case of imminent danger. This
sound is used in case of remote danger or in announcing something
unusual. As nearly as can be represented by letters it resembles
“e-c-g-k.” With this word I have often been warned by these little
friends. Nellie’s cage occupied a place near my desk. At night she
would always stay awake as long as the light was kept burning. Having
always kept late hours myself, I did not violate the rule of my life in
order to give her a good night’s rest. About two o’clock one morning,
when about to retire, I found Nellie wide awake. I drew a chair near
her cage and sat watching her pranks. She tried to entertain me with
bells and toys. Without letting her see it, I tied a long thread to a
glove and placed it in the corner of the room at a distance of several
feet away. Holding one end of the string, I drew the glove obliquely
across the floor. When I first tightened the string, which was drawn
across one knee and under the other, the glove slightly moved. This
her quick eye caught at the first motion. Standing almost on tiptoe,
her mouth half open, she cautiously peeped at the glove. Then in a
low undertone, verging on a whisper, she uttered the sound “e-c-g-k!”
Every second or so she repeated it, at the same time watching to see
whether or not I was aware of the approach of this goblin. Her actions
were very human-like. Her movements were as stealthy as those of a
cat. As the glove came closer and closer she became more and more
demonstrative. When at last she saw the monster climbing the leg of
my trousers she uttered the sound in a loud voice and very rapidly.
She tried to get to the object. She evidently thought it was a living
thing. She detected the thread with which the glove was drawn across
the floor, but she seemed in doubt as to what part it played in the
matter. Her eyes several times followed the thread from my knee to the
glove, but I do not think she discovered what caused the glove to move.
Having repeated this a few times, with about the same result each time,
I relieved her anxiety by allowing her to examine the glove. She did
this with marked interest for a moment and then turned away. I tried
the same thing again, but failed to elicit from her the slightest
interest after she had once examined the glove.
When Nellie first discovered the glove moving on the floor, she
attempted to call my attention in a low tone. As the object approached
she became more earnest and uttered the sound somewhat more loudly.
When she discovered the monster--as she regarded it--climbing up my
leg, she uttered the warning in a voice sufficiently loud for the
distance over which the warning was conveyed. These facts indicate that
her perception of sound was well defined. Her purpose was to warn me of
the approaching danger without alarming the object against which the
warning was intended. As the danger increased, the warning became more
urgent. When she saw the danger at hand, she no longer concealed or
restrained her alarm.
Nellie was an affectionate little creature. She hated to be left alone,
even when supplied with toys and a super-abundance of food. When she
saw me put on my overcoat or take my hat, she foresaw that she would
be left alone. Then she began to plead and beg and chatter. I often
watched her through a small hole in the door. When quite alone, in
perfect silence she played with her toys. Sometimes for hours together
she did not utter a word. She was not an exception to the rule that
monkeys do not talk when alone.
Although their speech is inferior to human speech, yet in it there is
an eloquence that soothes and a meaning that appeals to the human heart.
Briefly stated, the speech of monkeys and human speech resemble each
other in all essential points. The speech sounds of monkeys are
voluntary, deliberate, and articulate. They are addressed to others
with the evident purpose of being understood. The speaker shows that
he is conscious of the meaning which he desires to convey through the
medium of speech. He awaits and expects a reply. If it is not given,
the sound is repeated. The speaker usually looks at the one addressed.
Monkeys do not habitually utter these sounds when alone. They
understand the sounds made by others of their own kind. They understand
the sounds when imitated by a human being, by a phonograph, or by other
mechanical means. They understand the sounds without the aid of signs
or gestures. They interpret the same sound in the same way at all
times. Their sounds are made by their vocal organs and are modulated by
the teeth, the tongue, the palate, and the lips. Their speech is shaded
into dialects, and the higher forms of animals have higher types of
speech than the lower ones. The higher types are slightly more complex
and somewhat more exact in meaning than the lower ones. The present
state of monkey speech appears to have been reached by development
from lower forms. Each race or species of monkey has a form of speech
peculiar to its kind. When caged together for a time they learn the
meaning of each other’s sounds, but seldom try to utter them. Their
faculty of speech is commensurate with their mental and social status.
They utter their speech sounds loud or soft as the condition requires,
which indicates that they are conscious of the values. The more
pronounced the gregarious habits of any species, the higher the type of
speech it has. So far as I am able to discern, there is no intrinsic
difference between the speech of monkeys and the speech of men.