Chapter 4 Chapter III Development

The newly fertilized egg is a tiny cell 1/200th of an inch in diameter, not a human being, but a set of instructions for swimming into the uterine cavity.It is estimated that there are at least 250,000 pairs of genes in its spherical nucleus, of which 50,000 pairs determine the synthesis of proteins, and the rest regulate the speed of development. After the fertilized egg penetrates into the blood-filled uterine wall, it divides again and again, forming The new cells of the cells continue to grow, forming ridges, rings, and stacks.Then, these cells float like a magical kaleidoscope, and automatically gather to form a fetus with finely-shaped blood vessels, nerves and other complex tissues. Every division and transfer of the fetus is through the transfer of genes to the constituents of the cells. The chemical information exported by the outer layer of proteins, fats and carbohydrates is arranged.

After 9 months, the person is formed.From a functional point of view, it is a digestive tube surrounded by muscles and skin. As the newly formed heart rhythmically pumps blood into the closed blood vessels, various parts of the fetus are constantly renewed, and limited body movements are controlled by hormones and nerves. The reproductive organs are in the dormant stage, and they have to wait for several years before entering the second and final development according to the accurate signals sent by hormones, so as to complete the highest biological purpose of human beings, namely Reproduction, the top of the fetus is the brain.The brain weighs about a pound and is a thick paste. Its structure is as delicate as the most complex machine in the world. The human brain is composed of about 10 billion neurons (or nerve cells), and each neuron is combined with a Hundreds of thousands of other neurons are connected, and countless nerve fibers from the brain pass through the spinal cord. Here, they combine with other nerves to transmit information and instructions back and forth to various organs of the body. The brain and spinal cord are connected in series. The formed central nervous system receives electrical signals from no less than 1 billion receptors, including the rod-cone photoreceptor cells of the retina and the pressure-sensitive corpuscles of the skin.

The newborn seems to be an extremely precise circuit. Thousands of nerve cells direct the movement of the eyes. These cells are distributed fan-shaped in the eye muscles and in the reflex stations from the eye to the brain. With the guidance of higher integration centers scattered in the front visual field and other centers of the cerebral cortex, babies also have hearing. Sounds of various frequencies can stimulate a special set of receptors in his inner ear, and the receptors in turn transmit signals to higher-level corresponding organs in the brain. When the signal is transmitted to the brain, it is first sent out by the inner ear, just like the melody played by the keys of the piano, and then played again with a new diatonic scale in the middle of the back of the brain, and then transmitted to the hypothalamus of the midbrain and the forebrain The central geniculate body eventually enters the auditory cortex of the forebrain, where the mind "hears" in some unknown way,

This wonderful robot broke into the world under the care of his parents, and the rapid accumulation of experience soon transformed him into an independent thinking and independent feeling individual, and then he would acquire the basic elements of social behavior-language, cooperation, reason Anger from a wounded ego, love, familiality, everything that's uniquely human, but to what extent do the neuronal network devices that are surely encoded in the genes really predetermine the direction of social development?Could it be that the networked device that evolution has created is simply a multifunctional machine that can learn to adapt to any form of social existence?

This is, so to speak, our frame of reference from which to grasp every aspect of the empirical problem of human behavior: from 250,000 pairs of genes to 10 billion neurons, to a variety of unknown potential social systems, in the last In chapter 1, I used a comparison between humans and other social animals to demonstrate that human behavior at the same time was genetically limited. As predicted by evolutionary theory, behavioral development always led to the most common mammalian traits. However, our potential What is the maximum range of ?To what extent can humans straddle or even surpass the developmental pipeline of mammals?To get the answer, it is necessary to refer specifically to genetic determinism and to study the development of the individual.

We've finally touched on that key term: genetic determinism.The entire relationship between biology and the social sciences hinges on an understanding of genetic determinism, which, for those who categorically reject the implications of sociobiology, implies that any development is nothing more than a single insect-like developmental A mosquito's lifespan fits well with this narrow notion that a predetermined corresponding single behavioral pattern develops from a defined set of genes.After the winged adult mosquito emerges from the pupa, it only takes a few days to complete a series of complex behaviors until a batch of fertilized eggs are produced in organically polluted water. The humming sound of the mosquito's wings is very annoying, but to the male mosquito, it is a beautiful love song. The male mosquito flies towards the sound, which is an unprecedented experience for it. The buzz of the febrile female mosquito is between 450 and 600 Hz (cycles per second).In the lab, entomologists can attract male mosquitoes simply by tapping a tuning fork with this frequency.If you put a piece of cheesecloth over the tuning fork, some overexcited males try to copulate with the cloth.Female mosquitoes are less impatient, but the episodes of their lives still play to the strict instructions dictated by their genes.Female mosquitoes can find targets based on the body heat of humans and other mammals or the lactic acid smell from the skin of some animals. Skin, looking for blood vessels, sometimes found, sometimes not.At least one species of female mosquito recognizes blood by the smell of a chemical in red blood cells called adenosine diphosphate (ADP), the only significant sign of the hundreds of blood components available. Yes, as a sign of immediate approach, other similarly random "signal stimuli" lure the mosquito to a suitable pond or puddle where it can safely lay its eggs.

The mosquito is an automaton, it can't be anything else, and its tiny head has only about 100,000 nerve cells, each of which must be fully functional.The only way to accurately and successfully spend a lifetime within a few days is to rely on instinct—this is a series of rigid programs programmed by genes to ensure that mosquitoes can complete quickly and accurately from birth to final egg-laying behavior. On the contrary, the path of human spiritual development is circuitous and varied. Human genes prescribe the ability to develop a series of characteristics, not just a single characteristic. In certain types of behavior, this series of characteristics is limited. , and the results can be changed only by hard training—if possible—but in other types of behaviour, the range of traits is wide and the results are susceptible to change.

An example of restricted behavior is handedness, everyone has a biological tendency to be left-handed or right-handed.Currently, parents in Western societies are more tolerant of their children, so that children develop according to the genetic rules that affect this trait, but traditional Chinese society still emphasizes right-handed writing and eating through strong social pressure.In a recent study of Taiwanese children, Evelyn Deng and associates found that Taiwanese children had almost identical handedness for the two activities of writing and eating, but little or no activity in other activities for which they had not been specifically trained This consistency, therefore, allows genes to run their own course in this behavioral trait unless specifically influenced by conscious choice.

The evolution of ability is illustrated more vividly by a genetic disorder called phenylketonuria, the physiological side effect of which is mental retardation, caused by a recessive pair of genes among thousands of pairs of genes on human chromosomes. Caused by genes, people affected by the double phenylketonuria gene cannot use a common digestive substance - the amino acid phenylalanine. When the chemical breakdown of phenylalanine is blocked, abnormal intermediate products will accumulate in the body , the patient's urine turns black when exposed to the air and emits a distinct rat odor, about one in 10,000 children born has this genetic defect, unless phenylketonuric children grow toxins when they are 4 to 6 months old disappear, or he must suffer from untreatable mental retardation. Fortunately, this disaster can be avoided through early diagnosis and intake of foods low in phenylalanine. In phenylketonuria, the interrelationship between genes and environment through In the simplest form that can be imagined, it can be shown that the intelligence of babies born with two phenylketonuria genes can either develop normally or be impaired, but the possibility of impairment is very high. Therefore, an understanding of both genes and environment is necessary in order to predict with reasonable certainty whether a newborn will be mentally normal or hypoxic due to phenylketonuria.

Controlled by only one or two genes, behaviors as arbitrarily altered as phenylketonuric mental retardation are rare, and even in phenylketonuria, it is characterized by primary lesions rather than reactive subtleties Schizophrenia is one of the most common forms of psychosis and an example of a more typical relationship between genes and behavior. Schizophrenia is not a simple interruption or distortion of normal behavior. Some psychiatrists, most notably Thomas Sass and R. D. Lane, who believed that schizophrenia was nothing more than a crude stigma imposed by society on certain abnormal individuals, but these psychiatrists have been proved almost certainly wrong. Indeed, schizophrenia appears to be like A jumble of blind and strange reactions, including hallucinations, delusions, inappropriate emotional reactions, involuntary repetitive movements with no specific meaning, etc., and even death-like stupor caused by catatonic trance The changes are so subtle that psychiatrists have learned to treat each patient as a special case, the dividing line between the normal person and the schizophrenic is imperceptible, a large number of mild schizophrenics go unnoticed among the people, and Perfectly normal people are sometimes misdiagnosed as schizophrenics, but three extremes of schizophrenia are unmistakable: dysphoric, paranoid living between imaginary spies and assassins, clumsy and sometimes irresistible adolescent dementia, and panic catatonia, and while all people are at risk of developing schizophrenia, there are certainly certain individuals who have distinctly predisposing genes for the disease, acquired in infancy from parents with schizophrenia and Children raised by normal parents have a much higher rate of developing schizophrenia than children born to healthy parents who are later adopted. Seymour Katie and a team of American and Danish psychologists worked together to analyze Based on the data of hundreds of patients, a conclusive conclusion was drawn: the main cause of schizophrenia is heredity.

There is evidence that schizophrenia is widespread in other human societies as well.Jane Murphy found that from the Eskimos of the Bering Sea to the Yoruba of Nigeria, there are a series of symptoms similar to Western schizophrenia syndrome, and these patients are also regarded as mental illness - Eskimos call "trance patients" " (nutbkavibak), what the Yoruba call "were patients" (were) - these people became the main regular customers of tribal witch doctors and religious doctors; The same, accounting for between 0.4% and 0.7% of adults. Schizophrenia occurs in a much more complex manner than phenylketonuria and most other genetic forms of mental retardation, and it is not known whether it is caused by one or more genes.Physiological changes are evident in psychotic patients, and medical researchers may soon succeed in linking these changes directly to psychological disturbances. For example, Philip Seaman and Tyrone Leigh have found that some schizophrenic brains Key areas have twice the normal number of receptors for dopamine, the substance that transmits messages between nerve cells, an abnormality that could make the brain overly sensitive to its own signals and thus prone to hallucinations.However, there is some truth to traditional psychological theory, and the environment plays an important role in the occurrence of schizophrenia.The typical "schizophrenic" (schizophrenia-prone) family structure is an example.A family in which trust is broken, the exchange of ideas disrupted, parents who openly display mutual contempt, and unreasonable demands on their children, can easily develop a child with schizophrenic predispositions into an adult psychopath Some psychiatrists have even found that there is a kind of abnormal psychology in the mind of schizophrenic patients. This kind of person tries to create a secret inner world to escape his intolerable social environment. Predisposing to schizophrenia, a person with this gene can develop the disorder even when raised in a normal, supportive home environment. Therefore, even in relatively simple behavior types, human beings have the ability to acquire certain characteristics due to heredity, and can produce a tendency to learn a certain object among several possible objects, like Konrad Lorenz, Scientists with different philosophies, such as Robert Hind and Skinner, have emphasized that there is no sharp line between nature and nurture, and that we need new descriptions to replace the old-fashioned distinction between nature and nurture. The obvious ones, the most promising of which came from the ideas of the great geneticist Conran Waddington (died 1975).Development, says Waddington, is a bit like sloping terrain from the highlands to the coastline, and the development of certain traits—such as eye color, handedness, schizophrenia, or any other trait—is like rolling down the slope. Going ball, each feature is over a different stretch of terrain, and each feature is led by different types of ridges and canyons.In the case of eye color, given a set of blue or other genes that determine iris pigmentation, there is given a terrain, a single, deep channel into which the ball can only roll to one destination , as long as the eggs and sperm are combined, the eyes can only have one color. The terrain of mosquito development can also be imagined as a series of parallel unbranched valleys, one leading to sexual attraction caused by the sound of wings, and the other leading to towards automatic blood-sucking, and so on, until a dozen or so unrelated responses emerge, these canyons forming a series of precise, unalterable biochemical ) continues to neuromuscular actions transmitted by the mosquito brain. The development terrain of human behavior is much wider and more complex, but it is still a terrain. Sometimes, the canyon will bifurcate once or twice, and a person may eventually develop a right-handed habit or a left-handed habit.If genes or other biological influences predispose a person to be left-handed in the first place, it can be assumed that this branch of the person's developmental pipeline is deeper; will keep rolling down until it rolls into the left-handed channel, but if the parent trains the child to use the right hand, the ball will be squeezed into the shallower right-handed channel, the terrain of schizophrenia is wider where the various channels converge The network is more difficult to explore, and the path of the ball can only be predicted by statistical methods. The topographical statement is nothing more than a metaphor, certainly insufficient to account for the most complex phenomena, but it captures a crucial fact of human social behavior, each of which must be treated separately if its decisive significance is to be fully understood , and, in a way, explore it as a developmental process from genes to end result. Some forms of behavior may be better suited to the above analysis than others, and facial expressions showing basic emotions such as fear, disgust, anger, surprise and pleasure appear to be constant characteristics of all people, psychologist Paul Ekman These expressions of the Americans are the same as those of the extant Stone Age tribesmen in storytelling.When people from one culture are shown photos of people from another culture, they can identify facial expressions with more than 80 percent accuracy. Eleanor Eb-Ebsfeldt travels the world villages, and filmed locals exchanging ideas with gestures and facial expressions.To avoid making them self-conscious, he puts a prism in front of the camera lens.In this way, when shooting, he can not directly face the subject, so that he can form a 90-degree angle with the subject's face.Eb-Ebsfeldt records many signals that are widespread and even ubiquitous in both literate and preliterate cultures.A less common example is eyebrow mobilization, which in most cases is an involuntary jerk of the eyebrows as a friendly welcome. Yet another example of a universal signal that human ecobehavioralists are currently studying is smiling.In a purely zoological sense, smiling can be classified as an instinct.From 2 to 4 months, babies begin to smile and receive more care and affection from their parents immediately.Smiling is a social alleviator, in the words of zoologists, an innate, relatively constant signal for coordinating basic social relationships. A study of the smiles and other behaviors of infants and young children of the "Shrub People" tribe.When he started his daily observations, he “decided to write down what he had, and wrote it down according to the facts,” because Kunsang children were brought up under conditions very different from Western popular culture, and they were born by their mothers alone without anesthesia. In the next few months, they maintain almost uninterrupted physical contact with their mother or nurse. In the first three or four years, they are mostly placed in an upright position when they are awake, and they are fed several times an hour. They are trained to sit, stand, and walk more strictly. However, their smiling form and age of smiling are the same as those of American children, and they seem to play exactly the same role. It is more convincing proof that even blind children, Even deaf and blind children can produce smiles in the absence of any known psychological conditions conducive to laughter. It is entirely possible that this simplest and most automatic behavior is the result of a direct genetic link between the cells of the human brain and the nerves of the face, which causes the contraction pattern of the facial muscles to pass through a series of physiological events during early postnatal development. In the future, more rigorous research may reveal the existence of genetic variations that affect the pattern and intensity of neuromuscular activity. If these unexpectedly simple phenomena It did happen, and their discovery would set the stage for our first foray into the genetics of human communication. As man descends the developmental slope, his knowledge increases, and cultural influences become overwhelming, the terrain of human development is bound to undergo some changes in terms of language, clothing, and other culturally sensitive behaviors. Say, the terrain has become a vast delta with low ridges and winding loops. Consider in particular the maturation of language. There is evidence that the human brain is born with a certain structure to assemble sentences in a certain arrangement.According to Chomsky and some other language and psychologists, this "deep language" can make people master the language much faster than simple learning. There is never enough time to memorize English sentences by rote. Young children, unlike any other primate young, including young chimpanzees, have a strong drive to learn language. They babble, create vocabulary, experiment word meanings, quickly learn the rules of language in a predictable order, and the structures they create coincide with the grammatical forms of adults, but there are major differences in details. Roger Brown, a child development expert, aptly puts Children speak a language called their "first language," and comparisons of language ability between identical and dizygotic twins suggest that temporal variation in this development is in part genetically determined, and that comparisons of the topography of the upper slope of language development Simple, with deep channels, but, on the lower half of the broad slope, where the "second language," the complex adult language, emerges, the channels appear as shallowly etched networks that spread out in all directions, The outer manifestations of language change as culture evolves, and these changes are largely cultural evolution, with the subtlest pressures of education and fashion altering vocabulary, accent, and tempo. But what do the ridges and channels in the metaphor actually refer to?In some cases, it is powerful behavioral hormones that etch these channels, or other genetically determined biochemical formations during the formation of nerve cells, simple compounds that alter the ability of the nervous system to behave in a Rather than functioning the other way, perhaps equally important are the less obvious "learning rules," the steps and programs based on the activity of special populations of nerve cells that enable mastery Various forms of learning. The common view is that learning is a phenomenon suitable for all purposes, and that there is no difference in principle between the learning of various organisms. Many of the best psychologists, especially behaviorists such as Skinner, have stubbornly insisted that , most behaviors are shaped by some rudimentary learning, and placing animals in simplified laboratory settings where stimuli can be tightly controlled can reveal general laws governing learning, "The general environment in which behavior is performed is not important ’, Skinner wrote in 1938, ‘because at least the vast majority of specific operant behavior is the result of conditioning, I think that the dynamic character of operant behavior may be studied in terms of a single reflex.’ Skinner in His influential book Beyond Liberty and Dignity argued that these laws, once well understood, can be used to train people to lead happier and more fulfilling lives, beginning with the wisest Members of society design the culture, and children can then adapt to that culture without difficulty. These are powerful ideas, with correspondingly tantalizing precedents in the natural sciences.Substantial advances in these ideas have been made in the study of animal and human behavior.The central tenet of the behaviorist philosophy—that both behavior and spirit have a thoroughly materialistic basis capable of experimental analysis—is perfectly tenable.But the basic assumptions about the simplicity and balance of power of learning have collapsed, replaced by a variety of learning types that follow the general law, perhaps just evolution that excludes natural selection. It seems that each species A person's learning potential is determined by the structure of the brain and the continuous secretion of hormones, so it is ultimately determined by genes.Each animal is "easy" to learn certain stimuli, difficult to learn some others, and neutral to others.For example, adult great gulls quickly learn to recognize their own newly hatched chicks, but never their own eggs, which can also be distinguished visually, while newborn kittens are blind and crawl and are completely unable to stand on their own ．However, in order to survive, it must make a difference in some small aspects. A kitten is born with a superb learning ability. Using only its sense of smell, it can learn to crawl a short distance to find a feeding place in less than a day. Mother, with the help of smell or touch, it can remember the route and crawl along the mother's belly to the route to the nipple it likes; in the laboratory, it can quickly distinguish the artificial nipple according to the subtle difference in texture. Some people have also found a more impressive example. Every year, the blue 鵐 migrates from the spawning grounds in eastern North America to the wintering grounds in South America. Like many of our local birds, they also fly at night. The 鵐 already have the ability to distinguish the Polaris and circumpolar constellations, and they do this quickly and automatically, but their ability to distinguish other constellations is low.When domestic chickens drink water, if they give a weak electric shock to their beaks, and at the same time give some kind of visual stimulus, such as flashing a light, then they will avoid this visual stimulus in the future, but if they use the same method to give auditory stimulation, Like rattling noises, but they can't dodge. If you apply an electric shock to the chicken's feet, accompanied by noises, the situation will be just the opposite, that is, they can learn the sound signal, but they will not. Learning visual signals, this symmetry may seem strange at first glance, in fact, this is the survival law of animals with small brains. The chicken's program can be summed up by the following simple formula: , anything that affects the head, and anything audible that affects the feet. That is to say, some of the more stereotyped forms of animal instincts can be used as a basis for idiosyncratic forms of dispositional learning.But is human learning also biased?What we call human learning is certainly not a form of mechanical response like birds and blind kittens.We prefer to think that given enough time and willpower, we can learn anything; however, limitations remain.It must be admitted that even for geniuses and dedicated memory specialists there are clear limits to the quantity and complexity of what can be mastered, and we also recognize that one person may have an easier time mastering certain intellectual skills than others Much more interesting is that children acquire skills and emotions in a program that is difficult to change. Piaget, an outstanding Swiss developmental psychologist, spent his whole life describing the process of children's purer intellectual development, which is often surprising. Intellect develops along parallel but closely linked trajectories in complex conscious movement, concepts of meaning and cause and effect, space, time, imitation, and play.As the reflex-dominated infant becomes an egocentric and then a sociable child, the conception of reality gradually changes—from being preoccupied with moving objects to developing independent thinking about the movement itself; Piaget, who was originally trained in biology, believed that intellectual development is the interaction of innate genetic programs and the environment , it is no coincidence that he called this concept "genetic epistemology," the study of heredity actually opened the door to understanding. In his seminal books Attachment and Separation, John Bowlby traces back to comparable stages in the formation of the emotional bond by which children create a bond around their parents over the course of a few months. complex social environment.Linguistic psychologists have demonstrated that children acquire language in a time too precise and too short to be accounted for by simple memory, and at the same time Lawrence Kohlberg has shown that in the development of children's moral norms, Pia Jay-style stages of development also appear to be relatively short, and when these results are considered together we get the impression that people cannot create a sufficiently complex social environment through casual learning processes over a lifetime. That is to say, the human mind is not a pure blank slate on which experience can draw the most complex pictures with lines and dots, but rather, the human mind can be described as an autonomous decision-making machine and vigilant environmental scanner. sight, which first approaches certain types of choices over others, then innately favors some over others, and drives the body into action according to a flexible schedule according to which each People gradually move from infancy to old age automatically, the accumulation and memory of past choices, the consideration of future choices, and the re-experience of the emotions that made the choices, all of which constitute the spirit.The characteristics of a person's performance in the decision-making process distinguish him from other people.But the rules to be followed are so strict that there is a wide overlap in the decisions made by all people, and the resulting convergence is called human nature. While it is possible to approximate the relative stringency of control over various behavioral types, genetic studies based on comparisons of identical and dizygotic twins have shown that basic thinking, sensory, and motor skills are the most genetically influenced , while personality traits are least affected, and if this important result is confirmed by other studies, it can be inferred that the abilities required to cope with relatively constant problems in the physical environment develop along narrow channels , while those personality traits that represent adjustment to rapidly changing social environments are more adaptive. The evolutionary hypothesis points to other interrelationships of broad significance, such as the need for more emotional guidance for more important but less rational decision-making processes, a relationship that biologists can paraphrase as follows: "Most mental development is Consists of steps that must be taken quickly and automatically to ensure the survival and reproduction of the human race, and since the human brain can only be guided by rational thought to a limited extent, it has to resort to the help of the limbic system and other lower centers of the human brain Conveying the nuances of joy and pain. We can look for the kind of behavior most directly influenced by genetic evolution in unconscious, emotionally-charged learning rules. Take phobias as an example. Like many examples of animal learning, phobias often occur in childhood and have profound, Irrational emotional overtones, and difficult to eliminate, seem to make sense that phobias are often caused by snakes, spiders, rats, heights, enclosed places, and other factors that were potentially dangerous in ancient settings, but rarely by modern Caused by artifacts such as knives, guns, electrical outlets, etc., phobias probably provided the necessary leeway for survival in the early history of mankind; Sidewalk must be better. The incest taboo is an example of another major type of primitive learning, which, as the anthropologists Lionel Tegel and Robin Fox have pointed out, may well be seen as a more general relational mutual exclusion A special case of the principle.Once two people form a strong relationship, they find it difficult to mix emotionally with any other type of relationship. The process of teacher and student becoming colleagues is very slow, even if the student has long surpassed the teacher, mother and daughter. Rarely altering the color of the relationship they first formed, the incest taboo is pervasive in human culture, as father and daughter, mother and son, siblings feel that their initial relationship is almost entirely exclusive.In short, people are hindered in learning about relationships that exclude them. On the contrary, it is easy for people to learn the kinds of relationships that are genetically most favorable. The process of sexual union varies greatly between cultures, but the sexual union of all cultures is immersed in touching emotions. In cultures where emotion can be swift and profound, and produce a transcendent love that, once felt, changes the minds of young people forever. This aspect of human ecological behavior is unique to poets. Yaxing, as we see in James Joyce's excellent description: The girl stood still, motionless, gazing at the sea in front of him.She seemed to be a strange and beautiful sea bird conjured by magic.The bare legs are as slender and clean as the legs of a crane, and there is only a trace of emerald green seaweed stuck to them, like deliberately made symbols... The girly soft long blond hair, the girly handsome face, adorned with amazing The beauty of the world... When she felt his presence, felt the admiration in his eyes, she turned her eyes to him, silently endured his gaze, without shyness, without indulgence... Her image was already in his eyes. Eternal in his soul, not a single word breaks his ecstatic stillness. ("Portrait of a Young Artist") Logically, tendentious learning is formed at other transition points in the life cycle where people cling to their deepest feelings, for example, humans have a strong tendency to create various dividing lines, each When these boundaries are crossed, they formally transition from one existence to another, and cultures have elaborate transitional rites—initiations, marriages, confirmations, and inaugurations—that may still be protected by covert ceremonies. The influence of biological motive force.At all stages of life there is an equally strong desire to divide the rest of the human race into artificial and distinct categories, as if we could only divide the rest of the human race into members and non-members, relatives and non-relatives , friends and enemies, Erik Eriksson has pointed out.各处的人都有拟物种分类的倾向，而且都力图把外国社会贬低到次等物种的地位，并说他们不是完全的人，可以毫不内疚地贬低他们，甚至连温和的卡拉哈里桑族人也叫自己为昆——也就是人的意思，对于人类的这些先天倾向以及其他倾向，只有从遗传优势的角度来评价才有完全的意义，就象雄鸟用来保卫领地或宣布进攻的动人的春歌一样，它们都是富有美感的，只是我们有意识的头脑在开始的时候并没有意识到它们的真实意义而已。