VIII
THE MENTAL STATUS OF THE ORANG-UTAN
My first ownership of a live orang-utan began in 1878, in the middle of the Simujan River, Borneo, where for four Spanish dollars I became the proud possessor of a three-year old male. No sooner was the struggling animal deposited in the bottom of my own boat than it savagely seized the calf of my devoted leg and endeavored to bite therefrom a generous cross section. My leggings and my leech stockings saved my life. That implacable little beast never gave up; and two days later it died,—apparently to spite me.
My next orang was a complete reverse of No. 1. He liked not the Dyaks who brought him to me, but in the first moment of our acquaintance he adopted me as his foster-father, and loved me like a son. Throughout four months of jungle vicissitudes he stuck to me. He was a high-class orang,—and be it known that many orangs are thin-headed scrubs, who never amount to anything. His skull was wide, his face was broad, and he had a dome of thought like a statesman. He had a fine mind, and I am sure I could have taught him everything that any ape could learn.
During the four months that he lived with me I taught him, almost without effort, many things that were necessary in our daily life. Even the Dyaks recognized the fact that the "Old Man" was an orang (or "mias") of superior mind, and some of them traveled far to see him. Unfortunately the exigencies of travel and work compelled me to present him to an admiring friend in India. Mr. Andrew Carnegie and his then partner, Mr. J. W. Vandevorst, convoyed my Old Man and another small orang from Singapore to Colombo, Ceylon, whence they were shipped on to Madras, received there by my old friend A. G. R. Theobald,—and presented at the court of the Duke of Buckingham.
Up to a comparatively recent date, the studies of the psychologists that have been devoted to the minds of animals below man, have been chiefly concerned with low and common types. Comparatively few investigators have found it possible to make extensive and prolonged observations of the most intelligent wild animals of the world, even in zoological gardens, and their observations on wild animals in a state of nature seem to have been even more circumscribed. I know only three who have studied any of the great apes.
In attempting to fathom the mental capacity and the mental processes of some of the highest mammals, there is the same superior degree of interest attaching to the study of wild species that the ethnologist finds in the study of savage races of men that have been unspoiled by civilization. Obviously, it is more interesting to fathom the mind of a creature in an absolute state of nature than of one whose ancestors have been bred and reared in the trammels of domestication and for many successive generations have bowed to the will of man. The natural fury of the Atlantic walrus, when attacked, is much more interesting as a psychologic study than is the inbred rage of the bull-dog; and the remarkable defensive tactics of the musk-ox far surpass in interest the vagaries of range cattle.
For several reasons, the great apes, and particularly the chimpanzees and orang-utans, are the most interesting subjects for psychologic study of all the wild-animal species with which the writer is acquainted. Primarily this is due to the fact that intellectually and temperamentally, as well as anatomically, these animals stand very near to man himself, and closely resemble him. The great apes mentioned can give visible expression to a wide range of thoughts and emotions,
The voice of the adult orang-utan is almost absent, and only sufficient to display on rare occasions. What little there is of it, in animals over six years of age, is very deep and guttural, and may best be described as a deep-bass roar. Under excitement the orang can produce a roar by inhalation. Young orangs under two years of age often whine, or shriek or scream with anger, like excited human children, but with their larger growth that vocal power seems to leave them.
Despite the difference in temperament and quickness in delivery, I regard the measure of the orang-utan's mental capacity as being equal to that of the chimpanzee; but the latter is, and always will remain, the more alert and showy animal. The superior feet of the chimpanzee in bipedal work is for that species a great advantage, and the longer toes of the orang are a handicap. Although the orang's sanguine temperament is far more comforting to a trainer than the harum-scarum nervous vivacity of the chimpanzee, the value of the former is overbalanced, on the stage, by the superior acting of the chimp. For these reasons the trainers generally choose the chimp for stage education.
The chimpanzee is not only nervous and quick in thought and in action, but it is equally so in temper. It will play with any good friend to almost any extent, but the moment it suspects malicious unfairness, or what it regards as a "mean trick," it instantly becomes angry and resentful. Once when I attempted to take from our large black-faced chimpanzee, called Soko, a small lump of rubber which I feared she might swallow, my efforts were kindly but firmly thwarted. At last, when I diverted her by small offerings of chocolate, and at the right moment sought by a strategic movement to snatch the rubber from her, the palpable unfairness of the attempt caused the animal instantly to fly into a towering passion, and seek to wreak vengeance upon me. Her lips drew far back in a savage snarl, and she denounced my perfidy by piercing cries of rage and indignation. She also did her utmost to seize and drag me forcibly within reach of her teeth, for the punishment which she felt that I deserved.
A large male orang-utan named Dohong, under a similar test, revealed a very different mental attitude. He dexterously snatched a valuable watch-charm from a visitor who stood inside the railing of his cage, and fled with it to the top of his balcony. As quickly as possible I thrust my handkerchief between the bars, and waved it vigorously, to attract him. At once the animal came down to me, to secure another trophy, and before he realized his position I successfully snatched the charm from him, and restored it unharmed to its owner. Dohong seemed to regard the episode as a good joke. Without manifesting any resentment he turned a somersault on his straw, then climbed upon his trapeze and began to perform, as if nothing in particular had occurred.
The orang is distinctly an animal of more serene temper and more philosophic mind than the chimpanzee. This has led some authors erroneously to pronounce the orang an animal of morose and sluggish disposition, and mentally inferior to the chimpanzee. After a close personal acquaintance with about forty captive orangs of various sizes, I am convinced that the facts do not warrant that conclusion. The orang-utans of the New York Zoological Park certainly have been as cheerful in disposition, as fond of exercise and as fertile in droll performances as our chimpanzees. Even though the mind of the chimpanzee does act more quickly than that of its rival, and even though its movements are usually more rapid and more precise, the mind of the orang carries that animal precisely as far. Moreover, in its native jungles the orang habitually builds for itself a very comfortable nest on which to rest and sleep, which the chimpanzee ordinarily does not do.
I think that the exact mental status of an anthropoid ape is best revealed by an attempt to train it to do some particular thing, in a manner that the trainer elects. Usually about five lessons, carefully observed, will afford a good index of the pupil's mental capabilities. Some chimpanzees are too nervous to be taught, some are too obstinate, and others are too impatient of restraint. Some orang-utans are hopelessly indifferent to the business in hand, and refuse to become interested in it. I think that no orang is too dull to learn to sit at a table, and eat with the utensils that are usually considered sacred to man's use, but the majority of them care only for the food, and take no interest in the function. On the other hand, the average chimpanzee is as restless as a newly-caught eel, and its mind is dominated by a desire to climb far beyond the reach of restraining hands, and to do almost anything save that which is particularly desired.
Among the twenty or more orangs which up to 1922 have been exhibited in the Zoological Park, two stand out with special prominence, by reason of their unusual mental qualities. They differed widely from each other. One was a born actor and imitator, who loved human partnership in his daily affairs. The other was an original thinker and reasoner, with a genius for invention, and at all times impatient of training and restraint. The first was named Rajah, the latter was called Dohong.
Rajah was a male orang, and about four years of age when received by us. His high and broad forehead, large eyes and general breadth of cranium and jaw marked him at once as belonging to the higher caste of orangs. Dealers and experts have no difficulty in recognizing at one glance an orang that has a good brain and good general physique from those which are thin-headed, narrow-jawed, weak in body and unlikely to live long.
At the Zoological Park we have tested out the orang-utan's susceptibility to training, and proven that the task is so simple and easy that even amateurs can accomplish much in a short time. Desiring that several of our orangs should perform in public, we instructed the primate keepers to proceed along certain lines and educate them to that idea. Naturally, the performance was laid out to match our own possibilities. In a public park, where only a very little time can be devoted to training, we do not linger long over an animal that is either stupid or obstinate. Those which cannot be trained easily and quickly are promptly set aside as ineligible.
Without any great amount of labor, and with no real difficulty, our orangs were trained to perform the following simple acts:
1. To sit at table, and eat and drink like humans. This involved eating sliced bananas with a fork, pouring out milk from a teapot into a teacup, drinking out of a teacup, drinking out of a beer- bottle, using a toothpick, striking a match, lighting a cigarette, smoking and spitting like a man.
2. To ride a tricycle, or bicycle.
3. To put on a pair of trousers, adjust the suspenders, put on a sweater or coat, and a cap, reversing the whole operation after the performance.
4. To drive nails with a hammer.
5. Use a key to lock and unlock a padlock. The animal most proficient in this became able to select the right Yale key out of a bunch of half a dozen or more, with as much quickness and precision as the average man displays.
The orang Dohong learned to pedal and to guide a tricycle in about three lessons. He caught the two ideas almost instantly, and soon brought his muscles under control sufficiently to ride successfully, even under difficult conditions.
It was quickly recognized that our Rajah was a particularly good subject, and with him the keepers went farther than with the four others. From the first moment, the training operations were to him both interesting and agreeable. The animal enjoyed the work, and he entered into it so heartily that in two weeks he was ready to dine in public, somewhat after the manner of human beings.
A platform eight feet in height was erected in front of the Reptile House, and upon it were placed a table, a high chair such as small children use, and various dishes. To the platform a step- ladder led upward from the ground. Every day at four o'clock lusty Rajah was carried to the exhibition space, and set free upon the ground. Forthwith the keepers proceeded to dress him in trousers, vest, coat and cap. The moment the last button had been fastened and the cap placed upon his head, he would promptly walk to the ladder, climb up to the platform, and in the most business-like way imaginable, seat himself in his chair at the table, all ready to dine.
He used a napkin, ate his soup with a spoon, speared and conveyed his sliced bananas with his fork, poured milk from a teapot into his teacup, and drank from his cup with great enjoyment and decorum. When he took a drink (of tea) from a suspicious-looking black bottle, the audience always laughed. When he elevated the empty bottle to one eye and looked far into it, they roared; and when he finally took a toothpick and gravely placed it in his mouth, his auditors were delighted. Several times during the progress of each meal, Rajah would pause and benignly gaze down upon the crowd, like a self-satisfied judge on his bench.
Not once did Rajah spoil this exhibition, which was continued throughout an entire summer, nor commit any overt act of impatience, indifference or meanness. The flighty, nervous temper of the chimpanzee was delightfully absent. The most remarkable feature of it all was his very evident enjoyment of his part of the performance, and his sense of responsibility to us and to his audiences.
Rajah easily and quickly learned to ride a tricycle, and guide it himself. But for his untimely death, through a remarkable invasion of a microscopic parasite (Balentidium coli) imported from the Galapagos Islands by elephant tortoises, his mind would have been developed much farther. Since his death, in 1902, we have had other orang-utans that were successfully taught to dine, but none of them entered into the business with the same hearty zest which characterized Rajah, and made his performances so interesting.
We now come to a consideration of simian mental traits of very different character. Another male orang, named Dohong, of the same age and intellectual caste as Rajah, developed a faculty for mechanics and invention which not only challenged our admiration, but also created much work for our carpenters. He discovered, or invented, as you please, the lever as a mechanical force,—as fairly and squarely as Archimedes discovered the principle of the screw. Moreover, he delighted in the use of the new power thus acquired, quite as much as the successful inventor usually does. At the same time, two very bright chimpanzees of his own age, and with the same opportunities, discovered nothing.
[Illustration caption: THUMB-PRINT OF AN ORANG-UTAN
A group of fourteen experts in the New York City Departement of
Criminal Records were unable to recognise this thumb print as
anything else than that of a man]
[Illustration caption: "RAJAH," THE ACTOR ORANG-UTAN
In three lessons he learned to ride a tricycle]
Dohong was of a reflective turn of mind, and never was entirely willing to learn the things that his keepers sought to teach him. To him, dining at a table was tiresomely dull, and the donning of fashionable clothing was a frivolous pastime, On the other hand, the interior of his cage, and his gymnastic appliances of ropes, trapeze and horizontal bars, all interested him greatly. Every square inch of surface, and every piece of material in his apartment, was carefully investigated, many times over.
When three years old he discovered his own strength, and at first he used it good-naturedly to hector his cage-mate, a female chimpanzee smaller than himself. That, however, was of trifling interest. The day on which he made the discovery that he could break the wooden one and one-half inch horizontal bars that were held out from his cage walls on cast iron brackets, was for him a great day. Before his discovery was noted by the keepers he had joyfully destroyed two bars, and with a broken piece used as a lever was attacking a third. These bars were promptly replaced by larger bars, of harder wood, but screwed to the same cast-iron brackets that had carried the first series.
For a time, the heavier bars endured; but in an evil moment the ape swung his trapeze bar, of two-inch oak, far over to one side of his cage, and applied the bar as a lever, inside of a horizontal bar and from above. The new force was too much for the cast-iron brackets, and one by one they gave way. Some were broken off, and others were torn from the wall by the breaking of the screws that held them. Knowing that all those brackets must be changed immediately, Dohong was left to destroy them; which he did, promptly and joyfully. We then made heavy brackets of flat wrought iron bars, 1/2 by 21/2 inches, unbreakable even with a lever. These were screwed on with screws so large and heavy that our carpenters knew they were quite secure.
[Illustration caption: THE LEVER THAT OUR ORANG-UTAN INVENTED, AND
THE WAY HE APPLIED IT By W. A. Camadeo, in the "Scientific
American," 1907]
In due time, Dohong tested his lever upon the bars with their new brackets, and at first they held securely. Then he engaged Polly, his chimpanzee companion, to assist him to the limit of her strength. While Dohong pulled on the lever, Polly braced her absurd little back against the wall, and pushed upon it, with all her strength. At first nothing gave way. The combined strength exerted by the three brackets was not to be overcome by prying at the horizontal bar itself. It was then that Dohong's inventive genius rose to its climax. He decided to attack the brackets singly, and conquer them one by one. On examining the situation very critically, he found that each bracket consisted of a right- angled triangle of wrought iron, with its perpendicular side against the wall, its base uppermost, and its hypotenuse out in the air. Through the open centre of the triangle he introduced the end of his trapeze bar, chain and all, as far as it would go, then gave a mighty heave. The end of his lever was against the wall, and the power was applied in such a manner that few machine screws could stand so great a strain. One by one, the screws were torn out of the wood, and finally each bracket worked upon was torn off.
But there was one exception. The screws of one bracket were so firmly set in a particularly hard strip of the upright tongued- and-grooved yellow pine flooring that formed the wall, the board itself was finally torn out, full length! The board was four inches wide, seven-eighths of an inch thick, and seven feet long. Originally it was so firmly nailed that no one believed that it could be torn from its place. [Footnote: In the Winter of 1921 about a dozen newspapers in the United States published a sensational syndicated article, occupying an entire page, in which all of Dohong's lever discovery and cage-wrecking performances were reported as of recent occurrence, and credited to a stupid and uninteresting young orang called Gabong, now in the Zoological Park, that has not even the merit of sufficient intelligence to maintain a proper state of bodily uprightness, let alone the invention of mechanical principles.]
Without delay, Dohong started in with his lever to pry off the remaining boards of the wall, but this movement was promptly checked. Our next task consisted in making long bolts by which the brackets of the horizontal bars were bolted entirely through the partition walls and held so powerfully on the other side that even the lever could not wreck them.
As soon as the brackets were made secure, Dohong turned his attention to the two large sleeping boxes which were built very solidly on the balcony of his cage. Both of those structures he tore completely to pieces,—always working with the utmost good nature and cheerfulness. Realizing that they could not exist in the cage with him, we gave him a permit to tear them out—and save the time of the carpenters.
Dohong's use of his lever was seen by hundreds of visitors, and one frequent visitor to the Park, Mr. L. A. Camacho, an engineer, was so much impressed that he published in the Scientific American an illustrated account of what he saw.
For a long period, Dohong had been more or less annoyed by the fact that he could not get his head out between the front bars of his cage, and look around the partition into the home of his next- door neighbor. Very soon after he discovered the use of the lever, he swung his trapeze bar out to the upper corner of his cage, thrust the end of it out between the first bar and the steel column of the partition, and very deftly bent two of the iron bars outward far enough so that he could easily thrust his head outside and have his coveted look.
One of our later and largest orangs made a specialty of twisting the straw of his bedding into a rope six or seven feet long, then throwing it over his trapeze bar and swinging by it, forward and back.
Time and space will not permit the enumeration of the various things done by that ape of mechanical mind with his swinging rope and his trapeze, with ropes of straw twisted by himself, with keys, locks, hammer, nails and boxes. Any man who can witness such manifestations as those described above, and deny the existence in the animal of an ability to reason from cause to effect, must be prepared to deny the evidence of his own senses.
The individual variations between orangs, as also between chimpanzees, are great and striking. It may with truth be said that no two individuals of either species are really quite alike in physiognomy, temperament and mental capacity. As subjects for the experimental psychologist, it is difficult to see how any other could be found that would be even a good second in living interest to the great apes. The facts thus far recorded, so I believe, present only a suggestion of the rich results that await the patient scientific investigator. In the year 1915 Dr. Robert M. Yerkes, of Harvard University, conducted at Montecito, southern California, in a comfortable primate laboratory, six months of continuous and diligent experiments on the behavior of orang-utans and monkeys. His report, published under the title of "The Mental Life of Monkeys and Apes: A Study of Ideational Behavior," is a document of much interest and value. Dr. Yerkes' use of the orang-utan as a subject was a decided step forward in the study of "animal behavior" in America.