Part 3 (2/2)
The chief examples of anthropoid intelligence are told of the chimpanzee, which has been most frequently kept in captivity. It is usually lively and good-tempered and is very teachable. Some of the stories of its intelligence may be apocryphal, as those told by Captain Grandpre of a chimpanzee which performed all the duties of a sailor on board s.h.i.+p, and of one that would heat the oven for a baker and inform him when it was of the right temperature. But there are authenticated stories of chimpanzee intelligence which give it a high standing in this respect among the lower animals.
The emotional nature of the ape is also highly developed. It displays an affection equal to that of the dog, and a sympathy surpa.s.sing that of any other animal below man. The feeling displayed by monkeys for others of their kind in pain is of the most affecting nature, and Brehm relates that in the monkeys of certain species kept under confinement by him in Africa, the grief of the females for the loss of their young was so intense as to cause their death. More than once an ardent hunter has seen such examples of tender solicitude among monkeys for the wounded and of grief for the dead as to resolve never to fire at one of the race again.
James Forbes, in his ”Oriental Memoirs,” relates a striking instance of this kind. One of a shooting party had killed a female monkey in a banian tree, and carried it to his tent. Forty or fifty of the tribe soon gathered around the tent, chattering furiously and threatening an attack, from which they were only diverted by the display of the fowling-piece, whose effects they seemed perfectly to understand. But while the others retreated, the leader of the troop stood his ground, continuing his threatening chatter. Finding this of no avail, he came to the door of the tent, moaning sadly, and by his gestures seeming to beg for the dead body. When it was given, he took it sorrowfully up in his arms and carried it away to the waiting troop. That hunter never shot a monkey again.
This deep feeling for the dead is probably not common among monkeys. The gibbon, for instance, is said to take no notice of the dead. It is, however, highly sympathetic to injured and sick companions, and this feeling seems common to all the apes. No human being could show more tender care of wounded or helpless companions than has often been seen in members of this affectionate tribe of animals.
Without giving further examples of the intelligence and sympathy of the apes, we may say that they possess in a marked degree the mental powers to which man owes so much, viz. observation and imitation. The ape is the most curious of the lower animals--that is, it possesses the faculty of observation in an unusual degree. What we call curiosity in the ape is the basic form of the characteristic which we call attention or observation in man. Its seeming great activity in the ape is what might naturally be expected in an observant animal when removed from its natural habitat to a location where all around it is new and strange.
Man under like circ.u.mstances is as curious as the ape, while the latter in its native trees probably finds little to excite its special attention. In both man and the ape it needs novelty to excite curiosity.
Again, the ape is imitative in a high degree. This faculty also it does not share with the lower animals, but does with man, imitation being one of the methods by which he has attained his supremacy. Observation, imitation, education, are the three levers in the development of the human intellect. The first two of these the ape possesses in a marked degree. It is susceptible also to the last, being very teachable.
Education certainly exists to some extent among the apes in their natural habitat, perhaps to as great an extent as it did in primitive man. In the latter case it is doubtful if there was much that could be called designed education, the young gaining their degree of knowledge by observing and imitating their elders. The same is certainly the case among the apes.
We may reasonably ask what there is in the life and character of the apes to give them this mental superiority over the remaining lower animals. It is certainly not due to the arboreal life and powers of grasp of these animals, for in those respects they resemble the lemurs, which are greatly lacking in intelligence. Whether the monkeys emerged from the lemurs or the two groups developed side by side is a question as yet unsettled; at all events they are closely similar in conditions of existence. Yet while the monkeys are the most intelligent and teachable of animals, the lemurs are among the least intelligent of the mammalia. There is here a marked distinction which is evidently not due to difference of structure or habitat, and must have its origin in some other characteristic, such as difference in life habits.
There is certainly nothing in the diet of the ape to develop intelligence. The frugivorous and herbivorous animals do not need cunning and shrewdness to anything like the extent necessary in carnivorous animals. They do not need to pursue or lie in wait for prey; and they escape from their enemies mainly through strength, speed, concealment, or other physical powers or methods. Escape may occasionally develop mental alertness, but does not usually do so.
Certainly if the alert, watchful, suspicious habits of the apes are due to the requisite of avoiding dangerous enemies, we might naturally look for similar habits in the lemurs, which are similarly situated. And if we consider the wide distribution of the apes throughout the tropics of both hemispheres, and their great diversity in species and condition, it seems very unlikely that in all these localities their relations with other animals would be such as to develop the mental alertness which they so generally display. The fact appears to be that, while this may be a cause, it is not a leading cause, of mental development in animals, and that we must seek elsewhere for the origin of animal intelligence.
Research, indeed, leads us to examples of intelligence where we should least expect to find it. Among the mammalia we perceive one marked example in the beavers, the only one in the great cla.s.s of the rodents, with their nine hundred or more of species. But we must go still lower, to the insects, for the most striking examples, finding them alone in the ants, the bees, and the termites, among the vast mult.i.tude of insect forms. Less marked instances appear in the elephants, in some of the birds, and in certain other gregarious animals.
From these examples, and what is elsewhere known of animal intelligence, one broad conclusion may be drawn, that all the strikingly intelligent animals are strongly social in their habits, and that no decided display of intelligence is to be found among solitary species. This conclusion becomes almost a demonstration in the case of the ants and bees. The ants, for instance, comprise hundreds of species, spread over most of the world, mainly social, but occasionally solitary. The social species, while varying greatly in habit, all display powers of intelligence, and these so diversified as to indicate many separate lines of evolution.
The solitary ants, on the contrary, manifest no special intelligence, and do not rise above the general insect level. The same may be said of the bees. The hive bee, the most communal in habit, shows the highest traits of intelligent activity. The bees which form smaller groups and the social wasps stand at a lower level, and the solitary bees and wasps sink to the ordinary insect plane. We arrive at like conclusions from observation of the social termites, or white ants, some species of which are remarkable for their intelligent cooperation and division of duties.
Examples similar in kind may be drawn from the vertebrates. Among the birds there are none more quick-witted than the social crows, none with less display of intelligence than the solitary carnivorous species.
Birds are rather gregarious than social. There are few species whose a.s.sociation is above that of mere aggregation in flight. Those more distinctively social usually have special habits which indicate intelligence--as in the often cited instances of their seemingly trying and executing delinquents. Among the carnivorous mammals the social dog or wolf tribe displays the intelligent habit of mutual aid. The horses, oxen, deer, and other gregarious hoofed animals have a degree of division of duties, but their intelligence is of a lower grade than that of the dogs and the elephants. On the whole, it may be affirmed that the social habit is frequently accompanied by instances of special intelligence to which we find no counterpart among the solitary forms, and that the highest manifestations of intelligence in the lower animals are found in those forms which possess communal habits, as the ants, bees, termites, and beavers.
One important characteristic of the communal animals is that they become mentally specialized. They round up their powers, build barriers of habit over which they cannot pa.s.s, perform the same acts with such interminable iteration that what began as intellect sinks back into instinct. Each individual has fixed duties and is confined within a limited circle of acts, whose scope it cannot pa.s.s, or only to the minutest extent.
The non-communal social animals, on the contrary, are not thus restricted. Their intelligence is of a generalized character, and is capable of developing in new channels. None are tied down to special duties, each possesses the full powers of all, and they are thus more open to a continued growth of the intellect than the communal forms. To this cla.s.s belongs the ape. Its intelligence is general, not special; broadly capable of development, not narrowed and bound in by the limitation of certain fixed and special duties.
The suggestions above offered point to three grades of community among animals, which may be designated the communal, the social, and the solitary. Among these there are, of course, many stages of transition from one to the other. The specially communal, including the ants, bees, termites, and beavers, are those in which there is almost a total loss of individuality, each member working for the good of the community as a unit, not for its personal advantage. The result consists in organized industries, division and specialization of duties, a common home, food stock, etc. At a lower level in animal life, that of the hydroid polyps, communism has become so complete that the community has grown into an actual individual, the members not being free, but acting as organs of an aggregate ma.s.s, in which each performs some special duty for the good of the community.
The social animals differ from the communal in that the individuality of the members is fully preserved. There is some measure of work for the group, some degree of mutual aid, some evidence of leaders.h.i.+p and subordination, but these are confined to a few exigencies of life, while in most of the details of existence each member of the group acts for itself. The solitary animals are those which do not form groups larger than that of the family, and into whose life the principle of mutual aid, outside the immediate family relations, does not enter. Each acts for itself alone, and intercourse between the individuals of the species is greatly restricted.
The advantages of social habits among animals are evident. There is excellent reason to believe that all animals, and especially such advanced forms as the vertebrates and the higher arthropods, have some power of mental development, some facility in devising new methods of action to meet new situations. Though their reasoning power may be small, it is not quite lacking, and many examples of the exercise of the faculty of thought could be cited if necessary.
What we are here concerned with, is the final result of such exercises of individual thought powers. In the case of the solitary forms, such new conceptions die with the individual. Though they may exert an influence on the development of the nervous system, and aid in the hereditary transmission of more active brain powers, they are lost as special ideas, fail to be taken up and repeated by other members of the species. This is not the case with the social animals. Each of these has some faculty of observation and some tendency to imitation, and useful steps of advance made by individuals are likely to be observed and retained as general habits of the community. Anything of importance that is gained may be preserved by educative influences. The facility of mental communication between these creatures is perhaps much greater than is generally supposed, and acts of importance which are not directly observed might in many cases be transmitted through repet.i.tion for the benefit of the group. We know this to be the main agency in human progress. New ideas are of rare occurrence with man. Ideas of permanent value do not occur to one per cent., perhaps not to one hundredth of one per cent., of civilized mankind, yet few of such ideas are lost, and that which has proved of advantage to an individual soon becomes the common possession of a community.
Among the lower animals new and advantageous ideas are probably of exceedingly rare occurrence. When they do occur, their advantage to solitary forms is very slight, being that of minute steps of brain development and hereditary transmission of the same. To social forms they are doubly advantageous, since, while they tend to brain development, they may also be preserved in their original form, and transmitted directly to members of the group. They are still more advantageous to the communal animals, from the closer intercourse of these, and their constant a.s.sociation in acts of mutual aid. But in the latter instance their influence is usually exerted for the benefit of the community as a unit, while in the case of social animals it is of advantage to the individual.
The result of such a process of evolution in the case of the communal animals is a strict specialism. A series of acts of advantage to the community are slowly developed, and are repeated so frequently that they become instinctive, while a fixed circle of duties arises, through whose links it is almost impossible to break. There is no reason to believe that the individual initiative is wanting. The varied round of duties of a community of ants, for instance, could only have arisen through step after step of progress from the condition of the solitary ants. If such steps have been made, others may be made, and are likely to be preserved if found advantageous. The ant individual preserves its powers of observation and thought and may initiate new processes. But most of the ant communities are already so excellently adapted to the conditions of their life as to leave little opportunity for improvement, so that the adoption of new and advantageous habits are certain to be exceedingly rare.
It is an interesting fact that communalism has been confined to animals of comparatively low organization. The most complete examples of it exist in the polyps and some other low forms, in which each community has become a compound individual, the members remaining attached to the parent stock. The next higher examples to be met are the frequently cited ants and bees, belonging to the lowly organized cla.s.s of arthropoda, yet, through the advantage of a.s.sociation and mutual aid, developing actions and habits only found elsewhere in the human race.
The only example among vertebrates is that of the beavers, members of the low order of rodents. With these the results are less varied and intricate than with the ants, in accordance with the much smaller size of the community. All the higher vertebrates are either social or solitary in habit, and among them the narrow specialism of the communal forms does not exist. Each individual works in large measure for itself, its mental powers remain generalized, and it is not tied down to the performance of a series of fixed hereditary acts from which escape is well-nigh impossible.
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