Part 4
In pursuing possible measures of intellectual and intelligent capacity, what line should one pursue? I explored this question somewhat in _Man and Dolphin_, but wish to summarize and extend it here in this discussion. The invariants that we are seeking somehow do not seem to be as concrete as “tool-making and tool-using ability” by means of the hands which has been one of the major alleged criteria for human adaptation and success. The chimpanzee and the gorilla have the hands but they do not have the brains to back up the use of the hands. Man has both the hands and the brain. Thus we can quite simply and concretely contrast the performance of the large brains of man with his hands to the smaller brains of the primates with their hands. When we consider the whales, we seem obsessed, as it were, with the necessity of our own nature to look for an analog of the hand and the manipulative ability. May it not be better to find a more general principle than just handedness and its use?
I suggest that we think more in terms of a physiologically appropriate set of more general mechanisms which may subsume several other human functions under the same principle. It seems to me that we must look for abilities to develop generalized dexterity of use for certain kinds of end purposes for any or all muscular outputs from the central nervous system. If there is a task to be done, such as lifting a stone, whether in water or air, a given animal may turn it over with his foot, with his flipper, with his hand, with his tail, or with any other body part with which he could obtain a purchase on the stone. The end task is turning over the stone, to obtain food or whatever. It makes little difference what kind of muscular equipment he uses just so he uses it appropriately.
Let me illustrate with a more complex example seen in our own laboratory. A baby dolphin was being nursed in a small tank artificially. It apparently needed the constant attention of a human attendant. Its mother had not been caught with it. After several days it discovered that if it banged on the bottom of the tank with its flipper in a rhythmic fashion it could bring the humans from the other room. (We heard a loud thumping sound transmitted from a hydrophone in its tank.) Previous to this it attempted to bring the humans from the other room by whistling the distress call of the dolphins; unlike its mother, the humans did not respond to the whistle. In a sense this distress call is in his instinctual pattern for obtaining food and aid by other dolphins. The secondary adaptation and the new effort was that of manipulating the flipper rather than the phonation mechanism in the blowhole. Thus driven by whatever the instinctual need is, it tried different outputs from its brain and finally discovered one which brought the desired results. This ability to change the output from unsuccessful ones to successful ones seems to me to be evidence of a “higher nervous system” function. Of course in fine gradation and small differences, the same kind of pattern can be shown for smaller-brained animals. It is the seeking a new output, not necessarily instinctually tied in, and the radicalness of the change of output, plus the relating of many of the variables to one another thus generating the new output, that seems to be the hallmark of the large brain. These problems are not single variable ones with simple cause and effect, but are simultaneous multiple variable ones.
Among the manipulable outputs (muscular groups) I would include those of respiration and phonation. The dexterous and finely differentiated use of these muscles generates all the complexities of human speech. As more of the physiology and psychology of human speech are analyzed and made part of our sciences, the sharper will be our criteria for separating man from the other animals, and from those with smaller brains. Scientific descriptions of human speech are of relatively recent origin. Scientific descriptions of the physiology of the vocal tract are anything but a closed book at the present time. The neuroanatomy and neurophysiology of speech is in a relatively primitive state of development as a science. With such a lack of knowledge of the intimate and detailed mechanisms concerned, it would be rather presumptuous to evaluate at the present time their role in the measurement and testing of intelligence and intellectual capacity.
However, I wish to point out that these factors are important in such an evaluation and become even more important in terms of evaluating a species that is not human. Thus it is necessary, in order to evaluate the intelligence of even the dolphins, much less the whales, to know something of their abilities in the areas of phonation and other kinds of bodily gestures and manipulations and hence in their abilities to communicate with one another. As I implied in _Man and Dolphin_, it is not possible to measure accurately the intelligence of any other being than that of a human being, mainly because we do not exchange ideas through any known communication mode with such beings.
The difficulties of such understanding as we can possibly gain of the real situation of the whales in the sea and their adaptation as mammals to this particular environment, can be illustrated by their use of sonic generators for the location of their prey and of the boundaries of their container by means of the perception of echoes. As is well known, the small mammals, such as the bat, use this mechanism in air.[9] The bottlenose dolphin also uses this same kind of mechanism underwater.[7] [9][10] Because these animals are immersed in a medium of a density and a sound velocity comparable to the density and sound velocity of their own bodies, they can presumably use their sonar also in looking, as it were, inside one another’s body.[7] The sonar view of the inside of the body of a dolphin may possibly be very instructive to other dolphins and possibly even aid in diagnosis of the causes of certain problems, especially of those of the baby by the mother. For example, their buoyancy depends upon maintaining their center of gravity below their center of buoyancy; otherwise they turn over and drown. If the baby develops gas in stomach #1, he can develop problems in his buoyancy relationship which turn him over; however, the mother dolphin can probably easily find out whether or not there is a bubble of gas in the baby’s stomach by her echo ranging abilities. When she discovers such a bubble, she can then burp the baby by banging on the belly with her beak. We have seen such operations take place in our tanks. Here is another instance of the animal using a given output, coupled with the proper input, to diagnose a problem and to manipulate other outputs in the solution of that problem. How much of this is labeled “instinctual,” i.e., “unlearned,” is purely a matter of intellectual taste.
In the sea it is necessary to use sonic mechanisms for sightings and recognition. If one goes into the sea one realizes that one’s range of vision even under the best of circumstances is rarely beyond 100 feet and most of the time is less than that even near the brilliantly lit surface of the tropical seas. With sonic means, one’s range is extended up to several miles under the best of circumstances and under the worst to a few hundred feet.
Recently we have obtained evidence that shows that the dolphins communicate most of their information in the band of frequencies extending from about 8 kilocycles to 20 kilocycles by means of whistles and sonic clicks.[11] However, as shown by Schevill and Lawrence, they can hear sounds at least to 120 kilocycles[12] and as shown by Kellogg can produce sounds at least to 170 kilocycles.[10] We have recently been investigating the higher frequency bands in these animals and have reliable evidence that they can hear at least to 200 kilocycles and can produce sounds to at least 200 kilocycles.[7][13] With the proper electronic equipment one can listen to the nearer portions of the upper band and quickly determine that they can transmit in these bands without the necessity of transmitting in the (lower frequency) communication band. The high frequency information is broadcast in a narrow beam off the front of the beak as was first detected by Kenneth Norris.[14]
In these bands we find that they can produce musical tones or individual clickings or hissing-like noises. Recently we have found that an emotionally upset animal threatens other animals and humans by productions of very large amounts of energy both in the sonic communication band and in the ultrasonic bands. Recently we have had the opportunity of working with an old bull of 450 pounds weight who is so old his teeth have been ground down flat. In terms of his skeleton, he is the most massive animal we have ever seen. When he is irritated, his “barks” have sizable amounts of energy from about 0.5 to at least 300 kilocycles. He is also capable of transmitting in bands between 100 to 300 kilocycles without transmitting anything in the band from 8 kilocycles to 20 kilocycles in a narrow beam straight ahead of his body. When he is upset by the activities of a younger male, they face one another and blast at one another with short barks of this sort, meanwhile “threatening” by opening their mouths.
Since they live immersed in an acoustic world quite strange to us, we have great difficulty in appreciating the full life of these animals with respect to one another and their environment. From birth they are constantly bombarded with signals from the other animals of the same species and by echoes from the environment which they can apparently use very efficiently. Their ultrasonic (to us) emissions are not merely “sonar,” but are interpersonal and even emotional. These animals are not inanimate, cold pieces of sonar apparatus. They use their ultrasounds and their high-pitched sounds interpersonally with fervor in everything they do.[15]
We have demonstrated that the dolphins are quite capable of using vocal outputs as a demand for further rewards or for surcease from punishment. Their ability in the vocal sphere is quite sophisticated. In addition to the ultrasonic matters mentioned above, their sonic performance, when in close contact with man, is astonishing. In 1957 I discovered their ability to produce sounds similar to our speech sounds.[16] During the last two years we have had many opportunities to pursue further observations in this area. This emerging ability seems to be an adaptation to a new environment which includes Man.[17] They quickly discover that they can obtain various kinds of rewards by making what we now call “humanoid emissions.” When they make a sound which sounds similar to a human syllable or word, we express our pleasure by rewarding the animals in various ways. We have been exploring what some of these rewards are in order to elicit further such behavior under better control.
NAVTAE IN DORSA CETORVM, QVAE INSVLAS PVTANT, anchoras figentes sæpe periclitantur. Hos cetos Trolual sua lingua appellant, Germanice _Teüffelwal_.
We demonstrated that, like other animals, the monkey, the rat, etc., these animals can be rewarded by stimulating the proper places in their brains.[16][18] In a recent series of experiments we have been establishing the controls necessary to understanding what brain rewards mean in terms of natural physiology. We have demonstrated quite formally that rubbing the skin of these animals with our hands is a rewarding experience to them; they will seek it vocally and by body gestures and give certain kinds of performance in order to obtain this reward.
Recently we have found that “vocal transactions” are a reward to these animals.[7][13] (See below for human analogies in the child.) This seems to be one of the basic factors in our being able to elicit humanoid emissions. The vocal transactions are started by a human shouting some words over the water of the tank in which the animal is residing. A single word may be used or many words—it makes little difference. Eventually the animal in the tank will raise his blowhole out of water and make some sort of a humanoid emission or whistle or clicks in a delphinese fashion. If the human immediately replies with some word or words, the animal may immediately respond, the human answers, and a vocal transaction is under way. We have shown that dolphins naturally do this with one another in both their whistle and clicking spheres, and sometimes do it in the barking sphere.[13] How much of this is “instinctual” and how much is not, there is no way of knowing at the present time.
A physical analysis of such vocal transactions shows them to be formally quite as complex as the vocal transactions between human beings. In other words, the dolphin may say one word or a syllable-like emission, or many, one right after the other, as may the humans. If the human says one word, the dolphin may say one, two, three, or four, and if the human says one, two, three, or four, the dolphin may say one. There is no necessary master-slave kind of relationship in the delphinic emissions.
In our early reports we gave examples which were single words which sounded like the words that the human made.[16][7] This presentation led to misunderstandings among our scientific colleagues. It looked as if the animals were doing a slavish tape-recorder rendition of what we were doing in a fashion similar to that of a parrot or a Mynah bird. All along we have known that the dolphins did not do such a slavish job and were obviously doing a much more complicated series of actions. We are just beginning to appreciate how to analyze and what to analyze in these transactions. As I stated in _Man and Dolphin_ about 10% of these emissions sound like human speech. In other words, the dolphin is “saying” far more than we have transmitted to the scientific community to date. We hesitate to say anything more about this until we begin to understand what is going on in greater detail. We are making progress slowly.
Let me then make an appeal to you—a long appeal to your logical and rational views of man and cetaceans. Here I review the above points in more general terms, and develop a plea for a new science—a new discipline combining the best of science with the best of the humanities.
Several old questions should be revived and asked again with a new attitude, with more modern techniques of investigation and with more persistence. It may take twenty years or more to develop good answers; meanwhile the intellectual life of man will profit in the undertaking. There is something exciting and even at times disturbing in this quest.[19] The bits and pieces may have started before historical times. In each age of man a new fragment was allowed to be recorded and passed on to subsequent generations. Each generation judged and rejudged the evidence from the older sources on the basis of its then current beliefs and on the basis of its new experiences, if any. At times good evidence was attenuated, distorted, and even destroyed in the name of the then current dogma.
Today we have similar problems; our current beliefs blind us, too. Evidence right before the eye can be distorted by the eye of the beholder quite as powerfully as it has been in previous ages of man. We can only hope that we have achieved greater insight and greater objectivity than some of our ancestors. The winds and currents of bias and prejudice blow hard and run deep in the minds of men. In one’s own mind these factors are difficult to see, and when seen, difficult to attenuate and to allow for their influence. If at times I scold my own species, do not take it too personally; I am scolding myself more than you.
You can see by now that I believe that some of the answers to the quest are in our own minds. We must develop, imaginatively and humbly, numbers of alternative hypotheses to expand the testable areas of the intellect and bring to the investigation new mental instruments to test and to collect facts germane to our questions.
To ask about the intelligence of another species, we somehow first ask: how large and well-developed is its brain? Somewhat blindly we link brain size (a biological fact) to intelligence (a behavioral and psychological concept). We know, in the case of our own species, that if the brain fails to develop, intelligence also fails to develop.
How do we judge in our own species that intelligence develops or fails to develop? We work with the child and carefully observe its performances of common tasks and carefully measure its acquisition of speech quantitatively. We measure (among other factors) size of word vocabulary, adequacy of pronunciation, lengths of phrases and sentences, appropriateness of use, levels of abstraction achieved, and the quality of the logical processes used. We also measure speed of grasping new games with novel sets of rules and strategy; games physical and/or games verbal and vocal.
Normal mental growth patterns of human children have been measured extensively in both performance and in vocal speech acquisition. I have taken the liberty of relating these to the normal growth of brain weight of children.
TABLE I Threshold Quantities for Human Acquisition of Speech: Age and Brain Weight[7]
_Age_ _Brain _Speech stages_[9] (_first appearances_) (_months_) weight_[8] (_grams_)
2 480 Responds to human voice, cooing, and vocalizes pleasure. 4 580 Vocal play. Eagerness and displeasure expressed vocally. 6 660 Imitates sounds. 9 770 First word. 11 850 Imitates syllables and words. Second word. 13 930 Vocabulary expands rapidly. 17 1,030 Names objects and pictures. 21 1,060 Combines words in speech. 23 1,070 Uses pronouns, understands prepositions, uses phrases and sentences.
[7]Lilly, John C. _Man and Dolphin: A Developing Relationship_. London: Victor Gollancz, 1962.
[8]Boston Children’s Hospital data from 1,198 records, in Coppoletta, J.M., and Wolbach, S.B., “Body Length and Organ Weights of Infants and Children,” _American Journal of Pathology_, IX (1933), 55-70.
[9]Summarized from McCarthy, Dorothea, “Language Development in Children,” in Carmichael, Leonard, ed., _Manual of Child Psychology_. New York: John Wiley, 1946, pp. 476-581.
Table 1 shows relations between age, brain weight, and speech performance, up to 23 months, 1070 grams, and the use of full sentences. By 17 years, the brain reaches and levels off at 1450 grams and the number of words, levels of abstraction, etc., are so large as to be difficult to assess.
In these processes, what are the minimum necessary but not necessarily sufficient factors?[20] On the biological side, modern theory concentrates on two factors: total numbers of neurons and the number of interconnections between them. On the psychological side, modern theory concentrates on the numbers of occurrences of reinforced contingencies experienced, the number of repetitions, and the number of adequate presentations from the accepted set of the consensus known as “native language,” and the total numbers of sets in the stored memories at a given age. In addition, of course, is the adequate development of the transmitting and of the receiving equipment needed for speech and its ancillary behaviors.
On the biological side, modern neurology says the number of neurons in the human brain reaches maximum value before birth at about 13 billions. After this point, the increase in weight consists of increased numbers of fibers, increased connections, increased size of elements, and increased efficiency and selectivity of transmission. Thus the increase in weight of the human brain from about 400 to 1400 grams seems to be devoted to improving its internal (as well as external) communication, storage, and computation networks. As I have stated elsewhere (_Man and Dolphin_), it is my impression that there exist critical threshold values in the brain’s growth pattern at which certain kinds of performance become possible. Complex speech acquisition seems related to brain weights of 800 to 1000 grams, but no smaller. This assumes, of course, numbers of neurons (10¹⁰) and numbers of connections and opportunities for learning and time to learn commonly found with humans.