On Aggression

Konrad Lorenz

• Publisher: Routledge
• Year: 2005
• ISBN:
  9781134456574
• Edition: 1
• Topic: Psychologie
• Subtopic: Histoire et théorie en psychologie

Konrad Lorenz was the author of some of the most popular books ever published about animals, including the best-selling Man Meets Dog and King Solomon's Ring. On Aggression is one of his finest works, as well as the most controversial. Through an insightful and characteristically entertaining survey of animal behaviour, the Nobel Prize winner tracks the evolution of aggression throughout the animal world. He also raises some startling questions when he applies his observations of animal psychology to humankind. His conclusions caused an unprecedented controversy, culminating in a statement adopted by UNESCO in 1989 which appeared to condemn his work. Whether or not Lorenz actually claimed aggression is hard-wired into the human psyche, and that war is an inevitable result, is something readers can decide upon for themselves. However you react, there can be no doubting that in today's violent world this powerful work remains of paramount importance.

1

                                          

PROLOGUE IN THE SEA

My childhood dream of flying is realized: I am floating weightlessly in an invisible medium, gliding without effort over sunlit fields. I do not move in the way that Man, in philistine assurance of his own superiority, usually moves, with belly forward and head upward, but in the age-old manner of vertebrates with back upward and head forward. If I want to look ahead, the discomfort of bending my neck reminds me painfully that I am really an inhabitant of another world. But I seldom want to do this, for my eyes are directed downwards at the things beneath me, as becomes an earthly scientist.

Peacefully, indolently, fanning with my fins, I glide over fairy-tale scenery. The setting is the coast of one of the many little islands of coral chalk, the so-called Keys, that stretch in a long chain from the south end of the Florida peninsula. The landscape is less heroic than that of a real coral reef with its wildly cleft living mountains and valleys, but just as vivid. All over the ground, which consists of ancient coral rubble, can be seen strange hemispheres of brain coral, wavy bushes of corgonia and, more rarely, richly branched stems of staghorn coral, while between them are variegated patches of brown, red and gold seaweed, not to be found in the real coral reefs farther out in the ocean. At intervals are loggerhead sponges, manbroad and table-high, almost appearing man-made in their ugly but symmetrical forms. No bare surfaces of lifeless stone are visible, for any space between all these organisms is filled with a thick growth of moss animals, hydroid polyps and sponges whose violet and orange-red species cover large areas; of some organisms among this teeming assortment I do not even know whether they belong to the plant or the animal kingdom.

My effortless progress brings me gradually into shallower water where corals become fewer, but plants more numerous. Huge forests of decorative algae, shaped exactly like African acacia trees, spread themselves beneath me and create the illusion that I am floating not just man-high above Atlantic coral ground, but a hundred times higher above an Ethiopian steppe. Wide fields of turtle grass and smaller ones of eelgrass glide away beneath me, and now that there is little more than three feet of water beneath me, a glance ahead reveals a long, dark, irregular wall stretching as far as I can see to each side and completely filling the space between the illuminated sea-bed and the mirror of the surface: it is the border between sea and land, the coast of Lignum Vitae Key.

The number of fish increases rapidly, dozens shoot from under me, reminding me of photographs of Africa where herds of wild animals flee in all directions from the shadow of an aeroplane. In some places, above the fields of thick turtle grass, comical fat puffers remind me of partridges taking offfrom a cornfield zooming up only to glide down to land again in the next field or so. Other fish, many of which have incredible but always harmonious colours, do the opposite, diving straight into the grass as I approach. A fat porcupine with lovely devil’s horns over ultramarine blue eyes lies quite quietly and grins at me. I have not hurt him, but he – or one of his kind – has hurt me! A few days ago I thoughtlessly touched one of this species, the spiny boxfish, and the razor-sharp parrot-beak, formed by two opposing teeth, pinched me and removed a considerable piece of skin from my right forefinger. I dive down to the specimen just sighted and, using the labour-saving technique of a duck in shallow water, leaving my backside above the surface, I seize him carefully and lift him up. After several fruitless attempts to bite, he starts to take the situation seriously and blows himself up; my hand clearly feels the ‘cylinder strokes’ of the little pump formed by the pharyngeal muscles of the fish as he sucks in water. When the elasticity of his outer skin has reached its limit and he is lying like a distended prickly ball in my hand, I let him go and am amused at the urgency with which he squirts out the pumped-in water and disappears into the sea-weed.

Then I turn to the wall separating sea from land. At first glance one could imagine it to be made of volcanic tuff, so fantastically pitted is its surface and so many are the cavities which stare like the eyeholes of skulls, dark and unfathomable. In fact, the rock consists of coral skeletons, relics of the pre-Ice Age. One can actually see in the ancient formations the structure of coral species still extant today and, pressed between them, the shells of mussels and snails whose living counterparts still frequent these waters. We are here on two coral reefs: an old one which has been dead for thousands of years and a new one growing on the old, as corals, like cultures, have the habit of growing on the skeletons of their forebears.

I swim up to and along the jagged waterfront, until I find a handy not too spiky projection which I grasp with my right hand as an anchorage. In heavenly weightlessness, cool but not cold, a stranger in a wonderland far removed from earthly cares, rocked on gentle waves I forget myself and am all eye, a blissful breathing captive balloon!

All around me are fish, and here in the shallow water they are mostly small fish. They approach me curiously from a distance or from the hiding-places to which my coming had driven them; they dart back as I clear my snorkel by blowing out the water that has condensed in it; when I breathe quietly again they come nearer, swaying up and down in time with me in the gently undulating sea. It was by watching fish that, still with a clouded vision, I first noticed certain laws of animal behaviour, without at the time understanding them in the least, but ever since I have endeavoured to reach this understanding.

The multiplicity of the forms surrounding me – many so near that my long-sighted eyes cannot discern them sharply – seems at first overwhelming. But after a while their individual appearances become more familiar and my gestalt perception, that most wonderful of human faculties, begins to achieve a clearer, general view of the swarms of creatures. Then I find that there are not so many species as I thought at first. Two categories of fish are at once apparent: those which come swimming in shoals, either from the open sea or along the wall, and those which, after recovering from their panic at my presence, come slowly and cautiously out of a cave or other hiding-place – always singly. Of the latter I already know that even after days or weeks the same individuals are always to be found in the same dwelling. Throughout my stay at Key Largo I visited regularly, every few days, a beautiful ocellated butterfly-fish in its dwelling under a capsized landing-stage and I always found it at home. Among the fish wandering hither and thither in shoals are myriads of little silversides, various small herrings which live near the coast, and their untiring hunters, the needle-fish, swift as arrows. Then there are grey-green snappers loitering in thousands under landing-stages, breakwaters and cliffs, and delightful blue-and-yellow-striped grunts, so called because they make a grunting noise when removed from the water. Particularly numerous and particularly lovely are the blue-striped, the white, and the yellow-striped grunts, misnomers because all three are blue and yellow striped, each with a different pattern. According to my observations, all three kinds swim frequently in mixed shoals. These fish have a buccal mucous membrane of a remarkable burning-red colour, only visible when, with widely opened mouth, a fish threatens a member of its own species, which naturally responds in the same manner. However, neither in the aquarium nor in the sea have I ever seen this impressive sparring lead to a serious fight.

One of the charms of these and other colourful grunts, and also of many snappers, is the fearless curiosity with which they accompany the snorkel diver. Probably they follow harmless large fish and the now almost extinct manatee, the legendary sea-cow, in the same way, in the hope of catching little fish or other tiny creatures that have been scared out of cover by the large animal. The first time I swam out from my home harbour, the landing-stage of Key Haven Motel in Tarvenier on Key Largo, I was deeply impressed by the enormous crowd of grunts and snappers which surrounded me so densely that it obscured my view, and which seemed to be just as strong in numbers wherever I swam. Gradually I realized that I was always escorted by exactly the same fish and that at a modest estimate there were at least a few thousand. If I swam parallel with the shore to the next pier about half a mile away, the shoal followed me for about half this distance and then suddenly turned round and raced home as fast as it could swim. When the fish under the other landing-stage noticed my coming, a startling thing happened: from the darkness of the stage emerged a monster several yards high and wide, and many times this length, throwing a deep black shadow on the sunlit sea bottom as it shot towards me, and only as it drew very near did it become resolved into a crowd of friendly grunts and snappers. The first time this happened to me, I was terrified, but later on these fish became a source of reassurance rather than fear, because while they remained with me I knew that there was no large barracuda anywhere near.

Entirely different are those daring little predators, needlefish and halfbeaks, which hunt in small bands of five or six just under the surface. Their whip-like forms are almost invisible from my submarine viewpoint, for their silver flanks reflect the light in exactly the same way as the under-surface of the air, more familiar to us in its Janus face as the upper surface of the water. Seen from above, they are even more difficult to discern, since they shimmer blue-green just like the water surface. In widely spread flank formation they comb the highest layers of water hunting the little silversides which frequent the water in millions, thick as snowflakes in a blizzard and gleaming like silver tinsel. These dwarfs, the silversides, are not afraid of me, for fishes of their size would be no prey for fishes of mine. I can swim through the midst of their shoals and they give way so little that sometimes I hold my breath involuntarily to avoid breathing them in, as if I were passing through an equally dense cloud of mosquitoes. The fact that I am breathing through my snorkel in another medium does not in the least inhibit this reflex. If even the smallest needle-fish approaches, the little silversides dart at lightning speed in all directions, upward, downward, and even leaping above the surface, producing in a few seconds a large clear space of water, which only gradually fills up again when the predator has passed.

Although the shapes of the fat-headed grunts and snappers are so different from those of the fine, streamlined needle-fish, they have one thing in common: they do not deviate too much from the usual conception of the term ‘fish’. Among the resident cavedwellers the situation is different: the blue angel-fish, decorated in youth with yellow vertical stripes, can still be called a ‘normal fish’, but this thing pushing its way out of a crevice between two coral blocks, weaving with hesitating backward and forward movements, this velvet-black disc with bright yellow semi-circular transverse bands and a luminous ultra-marine-blue border to its lower edge, is this really a fish? Or those two little round things, the size and shape of a bumble-bee, hurrying by and displaying on their rear end a round eye bordered with blue? Or the little jewel shining from that hollow, whose body is divided by a diagonal line from the lower anterior to the upper posterior end into a deep violet-blue and a lemon-yellow half? Or this unique little piece of dark-blue starry-sky, strewn with tiny pale blue lights, which in paradoxical inversion of space is emerging from a coral block below me? On closer examination, all these fairy-tale figures are of course perfectly ordinary fishes, not too distantly related to my old friends and collaborators, the cichlids. The starry-sky, the marine jewel fish, and the little fish with the blue head and back and the yellow belly and tail, called beau gregory by the Floridians, are in fact close relations. The orange-red bumble-bee is a baby of the ‘rock beauty’, and the black and yellow disc is a young black angel-fish. But what colours, and what incredible designs: one could almost imagine they were planned to create a distant effect, like a flag or a poster.

The great, rippling mirror above me, starry-skies – if only tiny ones – below; swaying weightlessly in a translucent medium, surrounded by angels, lost in contemplation and awed admiration of the creation and its beauty, I thank the creator that I am still able to observe essential details: of the dull-coloured fishes or the pastel-coloured grunts I nearly always see several of the same species at once, swimming in close shoal formation; but of the brightly coloured species within my field of vision, there is one blue and one black angel-fish. Of the two baby rock beauties that have just raced by, one is in furious pursuit of the other.

I continue to observe, although, in spite of the warmth of the water, my captive-balloon position is making me feel cold. Now in the far distance – that is, only ten or twelve yards even in clear water – I see a beau gregory approaching, in search of food. The other beau, which is close to me, sees the intruder later than I do from my lookout post, and he only notices him when he is within about four yards. Then he shoots towards him furiously, whereupon the stranger, although he is a little bigger than his adversary, switches round and flees with vigorous strokes in wild zig-zags, trying to avoid the ramming movements of his pursuer; these, if they met their mark, could inflict severe wounds, and indeed one of them does for I see a glinting scale flutter to the bottom like a wilted leaf. As soon as the stranger has disappeared into the dusky blue-green distance, the victor returns to his hollow, threading his way calmly through a dense shoal of young grunts who are in search of food in front of the entrance, and the absolute equanimity with which he passes through the shoal gives the impression that he is dodging stones or other inanimate obstacles. Even the little blue angel-fish, not unlike himself in shape and colour, rouses not the least sign of his aggression.

Soon after I observe a similar altercation between two black angel-fish, scarcely a finger in length; but this time it is even more dramatic. The anger of the aggressor and the panicky flight of the intruder are even more apparent – though perhaps this is because my slow human eye is better able to follow the movements of the angel-fish than those of the far swifter beau gregorys, whose performance is too quick for me.

I now realize that I am rather cold, and as I climb the coral wall into the warm air and golden sun of Florida, I formulate my observations in a few short sentences: the brilliant ‘poster-coloured’ fish are all local residents and it is only these that I have seen defending a territory. Their furious attack is directed towards members of their own species only, except, of course, in the case of predatory fish in which, however, the motive of the pursuit is hunger and not real aggressiveness. Never have I seen fish of two different species attacking each other, even if both are highly aggressive by nature.

2

CORAL FISH IN THE LABORATORY

In the previous chapter I made use of poetic licence: I did not mention that I already knew from observations in the aquarium how furiously the brightly coloured coral fish fight their own species, and that I had already formed an opinion on the biological meaning of these fights. I went to Florida to test this hypothesis and if the facts disproved it I was ready to throw it overboard – or rather to spit it out through my snorkel, for one can hardly throw something overboard when one is swimming under water. It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.

Some years ago I began to study brightly coloured reef fish in the aquarium, impelled not only by my aesthetic pleasure in their beauty but also by my ‘flair’ for interesting biological problems. The first question that occurred to me was: why are these fish so colourful? When a biologist asks ‘What is the aim or purpose of something?’ he is not trying to plumb the depth of meaning of the universe or of this problem in particular, but he is attempting much more humbly to find out something quite simple and, in principle, open to solution. Since we have learned, through Charles Darwin, about evolution and even something about its causes, the question, ‘What for?’ has, for the biologist, a sharply circumscribed meaning. We know that it is the function of an organ that alters its form, in the sense of functional improvement; and when, owing to a small, in itself fortuitous, hereditary change, an organ becomes a little better and more efficient, the bearer of this character, and his descendants, will set a standard with which other, less talented members of his species cannot compete; thus in the course of time those less fit to survive will disappear from the earth’s surface. This everpresent phenomenon is called natural selection and is one of the two great constructors of evolution. The other constructor is mutation, which, together with the recombination of hereditary characters through sexual reproduction, provides the material for natural selection. With remarkable foresight, Darwin postulated mutation as a necessity at a time before even the term had been coined.

All the innumerable, complex and expedient structures of plant and animal bodies owe their existence to the patient work performed in the course of millions of years by mutation and selection. We are even more convinced of this than Darwin was, and, as we shall soon see, with more justification. To some people it may seem disappointing that the many forms of life, whose harmonious laws evoke our awe and whose beauty delights our aesthetic senses, have originated in such a prosaic and causally determined way. But to the scientist it is a constant source of wonder that nature has created its highest works without ever violating its own laws.

Our question ‘What for?’ can receive a meaningful answer only in cases where both constructors of evolution have been at work in the manner just described. Our question simply asks what function the organ or character under discussion performs in the interests of the survival of the species. If we ask ‘What does a cat have sharp, curved claws for?’ and answer simply by saying, ‘To catch mice with’, this does not imply a profession of any mythical teleology, but the plain statement that catching mice is the function whose survival value, by the process of natural selection, has bred cats with this particular form of claw. Unless selection is at work, the question ‘What for?’ cannot receive an answer with any real meaning. If we find, in a central European village, a population of mongrel dogs some of whom have straight tails and others curly ones, there is no point whatever in asking what they have such tails for. This random variety of forms – mostly more or less ugly – is the product of mutation working by itself, in other words, pure chance. But whenever we come upon highly regular, differentiated and complicated structures, such as a bird’s wing or the intricate mechanism of an instinctive behaviour pattern, we must ask what demands of natural selection caused them to evolve, in other words, what they are for. We ask this question with assurance, in the confident hope of an intelligible answer, for we have found that we usually get one provided the questioner perseveres enough. This is not disproved by the few exceptional cases where scientific research has not yet been able to solve some of the most important of all biological problems, such as the question of what the wonderful forms and colours of mollusc shells are for, as the inadequate eye of these animals cannot see them, even when they are not – as they often are – hidden by the skin-fold of the mantle and in the darkness of the deep-sea-bed.

The loud colours of coral fish call loudly for explanation. What species-preserving function could have caused their evolution? I bought the most colourful fishes I could find and, for comparison, a few less colourful and even some really drab species. Then I made an unexpected discovery: in the case of most of the really flamboyant poster-coloured coral fish, it is quite impossible to keep more than one individual of a species in a small aquarium. If I put several members of the same species into the tank, there were vicious fights and within a short time only the strongest fish was left alive. Later, in Florida, it impressed me deeply to watch in the sea the same scene that I had always observed in my aquarium after the fatal battles: several fish, but only one of each species, each brightly coloured but each flying a different flag, living peaceably together. At a small breakwater near my hotel, one beau gregory, one small black angel-fish and one butterfly-fish lived in peaceful association. Peaceful coexistence between two individuals of a poster-coloured species occurs, in the aquarium or in the sea, only among those fish that live in a permanent conjugal state. Such couples were observed, in the sea, among blue angel-fish and beau gregory, and in the aquarium among brown, and among white-and-yellow butterfly-fish. The partners are inseparable and it is interesting to note that they are more aggressive toward...