Darwin's Island (11 page)

Carnivory, which began with shortage, may perish with excess and insects at least can breathe a sigh of relief. To an evolutionist, the shared fate of nitrogen-fixing bacteria and fungi, of the Venus flytrap and the sundew, and of trees and their ants, is further proof, as their diverse talents disappear, that under natural selection, and in both life and death, parallel lines may converge.

CHAPTER III

SHOCK AND AWE

Many American politicians have taken pleasure in gloating over the fact that Zacarias Moussaoui, the Frenchman accused of involvement in the Twin Towers disaster, will certainly go mad, held as he is in solitary confinement in the Colorado ‘Supermax’ prison. As the judge who passed sentence said: ‘You will never get a chance to speak again . . . and will die with a whimper.’

The eminent jurist was not quite justified in his satisfaction at his captive’s fate, for many of the tens of thousands kept in endless isolation in American prisons end their lives not with a whimper, but a scream. Some do fall into insanity in such places, but much as the religious right might celebrate their mental decay, they would be dismayed to learn that Moussaoui will lose his mind for Darwinian reasons. Guy the Gorilla, star of London Zoo in the 1950s, was admired for his solemn disposition. In fact, the animal was deeply depressed, kept as he was for years alone in a small cage (although unlike his human equivalents he had no opportunity for suicide).
Homo sapiens
is a social primate and - like gorillas or chimpanzees - descends from an ancestor with the same habits. Had our forefathers been solitary beasts like the orang-utan, which spends most of the year alone, the worst of all punishments would not be solitary confinement but an endless dinner party. The constant exchange of subtle emotional cues around the table would drive all those present to their wits’ end.

Science is often asked to explain what makes men different from chimpanzees or orangs but in many ways that is not a scientific issue at all. Such questions deal with the mind rather than the body or the brain; a topic that most competent biologists consider to be outside their expertise. Even so, as scientists compare man’s anatomy and behaviour with that of his relatives, biology does reveal a little about how humans became what they are. We are, says all the evidence, creatures that crave society. To satisfy that yearning we spend large parts of our time in silent and sometimes subliminal conversation with each other.

Rousseau had a different view of the origin of human nature. He saw man as in decline from a pure and animal state and modern society as a corruption of what the world should be. ‘Savage man, left by Nature to bare instinct alone . . . will begin with purely animal functions . . . His desires do not exceed his physical needs: the only goods he knows in the Universe are food, a female, and rest.’ The true life was near-solitude, on a remote island best of all, with a bare minimum of interaction with others. The French philosopher’s ideas were romantic, but wrong. Members of all communities, human or otherwise, must negotiate to maintain peace, to have sex and to reap the benefits of cooperation. They use signals both self-evident and subtle to test the mental state of their fellows and to advertise their own, and even the solitary orang hoots now and again to impress its neighbours. Civilisation is based on the ability to respond to another’s sentiments and to express a mood of one’s own.

In 1879, at the Derby, Darwin’s cousin Francis Galton noted that he could assess ‘the average tint of the complexion of the British upper classes’ as he observed the crowd through his opera-glass. Then the race started, and in a letter to
Nature
entitled ‘The Average Flush of Excitement’, he observed that it became ‘suffused with a strong pink tint, just as though a sun-set glow had fallen upon it’. A shared hue was a statement of a common passion and Galton could work out what it was even when he could not tell individuals apart. In the same way, someone exposed to an image of a group of people who bear a range of expressions from happy to miserable can sense their general state of mind far faster than he could by scanning each visage separately. Our brain, it seems, has a filter that picks up not just how many are in a crowd, but how, on average, they feel. The ability has its down-side. Mass hysteria can spread through society as shared sentiments feed on themselves; as Charles Mackay put it in his 1841 book
Extraordinary Popular Delusions and the Madness of Crowds
, in an account of the South Sea Bubble and other mass fantasies, men ‘go mad in herds, while they only recover their senses slowly, and one by one’.

 

In 1872, in
The Expression of the Emotions in Man and Other Animals
, Darwin discussed the role of signals in the herds, packs, flocks, towns and cities in which social animals come together. The book was a first attempt to understand our own sentiments in scientific terms. He was interested in how mental actions are manifest in the face and the body and realised how closely the displays of inner feeling made by men and women resemble those of animals. The book discusses instinct, learning and reflexes in creatures as different as moths and apes. Its author knew that elephants wept and hippopotami sweated with pain and when he heard a cow grind her jaws in agony he was reminded of the gnashing of teeth in hell. He saw that loneliness, fear or anger and their outer signs have all - like limbs or eyes - evolved. Kick a dog and it crouches and turns down the corners of its mouth; torture an al-Qaeda suspect and he does the same.
The Expression of the Emotions
makes a powerful case for the shared mental descent of humans, primates, dogs and more.

Our own sentiments have long been compared to those of other creatures. The seventeenth-century painter Charles Le Brun, who is referred to in the
Emotions
book as a pioneer in the study of human feelings, urged those who tried to portray their subject’s mood to scrutinise beasts first. A few hours with swine, lascivious, gluttonous and lazy as they were, would, he was sure, help depict the inner life of a debauchee. Charles Darwin’s friend George Romanes went further. He set out a scale with fifty ranks. Worms and insects came in at step 18 as they could experience surprise and fear; dogs and apes were equal at point 28 as each had ‘indefinite morality along with the capacity to experience shame, remorse, deceit and the ludicrous’. Levels 29 to 50 were reserved for men or women of greater or lesser virtue.

Psychology is still marked by such ideas.
Emotions
’ central theme was, as ever, a world in which all of life’s attributes, from anatomy to anguish, emerge from shared descent. Science uses that logic on elephants, cows, apes, fruit flies and bacteria in its attempts to build a shared narrative of inner feelings. Those who transmit their sentiments expect a response from those who receive them. That two-way commerce involves a need to acknowledge, to copy and to respond to the moods of others. People gasp in sympathy at a sad tale, gaze at where another person’s eyes are directed or avoid food that someone else has rejected. Such reflections of another individual’s mental state are part of what makes us human.

Charles Darwin, a practical man, had little interest in philosophy. Even so, he realised that the biology of the mind was harder to interpret than was that of the body. He wrestled with the issue in rather the same way as modern psychologists try to come to grips with some of their own sometimes murky ideas. Can our thoughts be explained just as the ‘direct action of the excited nervous system on the body, independently of the will’ and if so, what (if anything) does that mean? Shakespeare speaks of Cardinal Wolsey when ‘Some strange commotion/ Is in his brain; he bites his lip and starts;/ Stops on a sudden, looks upon the ground . . .’ That, Darwin writes, came from the ‘undirected overflow of nerve-force’ - but is that phrase just an attempt to avoid deeper and less tractable questions? The task was made harder by his quarrel with the anti-evolutionist Charles Bell, author of the standard text on facial anatomy. Bell was convinced - and he was wrong - that humans had unique muscles divinely designed to express morality, spirituality or shame: a notion not of much help to someone anxious to understand the smile or the blush, but an early example of the preconceived truths that still plague many attempts to understand the human mind.

After a long stumble through the Freudian fog, the study of the mental universe has once again become a science, even if the many claims to have found the neural foundations of society do not yet deserve that status. Now, physicists and chemists busy themselves with questions once raised only by intellectuals. In institutes of psychiatry and neurology, cats, mice and dogs are used to dissect human habits. Even bacteria behave in a rational fashion when they settle down close to a source of food, or join hands with their colleagues to form a sticky film over teeth or wounds. Certain fruit-fly genes lead to homosexual behaviour and others to loss of memory, which might one day help in the study of illnesses such as Alzheimer’s disease. In mice and monkeys, experiments on brains once done with a scalpel are now carried out with machines of fantastic complexity. They are also used on people with brains damaged by strokes or accidents, while drugs help understand the mental universe of the normal, the reckless and the insane. Many of the questions raised in
The Expression of the Emotions
have a notably modern air and many remain unanswered.

Emotions
is in some ways a less satisfactory work than are the plant, barnacle or earthworm books and an unusual note of apology creeps in: ‘Our present subject is very obscure . . . and it always is advisable to perceive clearly our ignorance’ (and there its author was franker than some of his successors). Charles Darwin soon found that even what looked simple - the objective description of the facial expression of a man or a dog, for example - was hard, while to represent the sentiments behind it was even harder. That problem, in spite of the wonders of electronics, still baffles students of the nervous system. He was suspicious of phrenology - the notion that particular segments of the brain are associated with, for example, obstinacy, pride or guile - even if an admirer had claimed that the naturalist’s own head had ‘the bump of reverence developed enough for ten priests’. He struggled long and hard with the question as to just where felt experiences might be seated.

 

The student of the inner world looked first at the animals and children of his own household. As a kind-hearted man, he was careful not to disturb them too much, although his book does contain images of frightened babies that would see him accused of cruelty today. His sons, he noted, never pouted, although Francis’s mouth assumed that expression when he played the flute. He did not hesitate to play the animal himself. Francis remembered that his father’s body was very hairy, and that the great man would growl like a bear when his children put their hands inside his shirt.

Even in play the
Beagle
’s naturalist was serious, and he soon identified some general rules about human and animal behaviour. Intimations of happiness or grief, of welcome or rejection and of other opposed sentiments often came as mirror images. Thus, a frown is the opposite of a smile and a look of surprise the converse of a greeting. Some gestures emerged from movements that once had a function of their own. To beg with open hands is related to the posture taken when holding food and, in the same way, a person who rejects an advance closes his eyes and looks away, as if from an unpalatable meal. Animals seemed to follow similar rules and the paterfamilias of Down House saw almost the same downcast looks in his household pets as those adopted by his infant son.

From such simple observations emerged the science of comparative psychology. It began with dogs.

Pets gain their status because they seem, to their owners at least, to be almost human. Darwin was no exception and kept a dog - Sappho by name - even when he was a student. He saw no problem in describing canine sentiments in the same terms as our own. His pet when in ‘a humble and affectionate frame of mind’ acted in a way quite different from that of a hostile animal with its bristling hair and stiff gait. The ‘principle of antithesis’ was hard at work, for opposed sets of muscles were set into action to express contrasting emotions. The ‘piteous, hopeless dejection’ of his favourite hound when it discovered that it was not about to go out for a walk but instead was to sit in on an experiment in the greenhouse was manifest in a ‘hothouse face’, the ‘head drooping much, the whole body sinking a little and remaining motionless; the ears and tail falling suddenly down, the tail by no means wagged’. That was quite different from its expression when happy and excited, with the head raised, ears erect and tail aloft.

As well as such individual shifts of mood the proud pet-owner noted marked differences in personality among breeds. Descent with modification could, it appeared, change minds as easily as it could bodies. Certain kinds, such as the terrier, grinned when pleased while others did not. Spitz-dogs - huskies, elkhounds and the like - barked while the greyhound was silent. The canine universe encompasses a wide range of talents. Some varieties herd sheep and cattle (and, in the case of the Portuguese Water Dog, chivvy fish instead) while others guard, hunt, guide or annoy the general public. The various breeds when taken together show a wider range of behaviour than that found among all wild canines - wolves, foxes, coyotes and jackals - across the world. Many of the differences are innate, and
The Origin
tells of a cross with a greyhound which gave a family of shepherd dogs a tendency to hunt hares. So impressed was its author with the animals’ divergence in habits that he suggested some of the household types had descended from distinct wild ancestors (and there he was wrong).