Intelligence

A New Look

Hans Eysenck

• Publisher: Routledge
• Year: 2018
• Print ISBN: 9781138526198
• eBook ISBN: 9781351310024
• Topic: Psychology
• Subtopic: Cognitive Psychology & Cognition
• Index: Psychology

The concept and measurement of intelligence present a curious paradox. On the one hand, scientists, fluent in the complex statistics of intelligence-testing theories, devote their lives to exploration of cognitive abilities. On the other hand, the media, and inexpert, cross-disciplinary scientists decry the effort as socially divisive and useless in practice. In the past decade, our understanding of testing has radically changed. Better selected samples have extended evidence on the role of heredity and environment in intelligence. There is new evidence on biology and behavior. Advances in molecular genetics have enabled us to discover DMA markers which can identify and isolate a gene for simple genetic traits, paving the way for the study of multiple gene traits, such as intelligence.

Hans Eysenck believes these recent developments approximate a general paradigm which could form the

basis for future research. He explores the many special abilities verbal, numerical, visuo-spatial memory that contribute to our cognitive behavior. He examines pathbreaking work on "multiple" intelligence, and the notion of "social" or "practical" intelligence and considers whether these new ideas have any scientific meaning. Eysenck also includes a study of creativity and intuition as well as the production of works of art and science identifying special factors that interact with general intelligence to produce predictable effects in the actual world.

The work that Hans Eysenck has put together over the last fifty years in research into individual differences constitutes most of what anyone means by the structure and biological basis of personality and intelligence. A giant in the field of psychology, Eysenck almost single-handedly restructured and reordered his profession. Intelligence is Eysenck's final book and the third in a series of his works from Transaction.

1
The Paradox of Intelligence and Its Measurement

The concept of intelligence, and its measurement, present us with a curious paradox. On the one hand, we have hardboiled scientists devoting their lives to the exploration of cognitive abilities, and expert in the complex statistics that are involved in testing theories about intelligence, regarding this body of work as an outstanding success of experimental psychology, marking the first triumph in actually measuring, with considerable accuracy, a mental quality. On the other hand, we have journalists, media people, and even the occasional scientist drifting in from other disciplines, not expert, or even knowledgeable in the field, decrying the whole effort as a waste of time, futile busywork, socially divisive, and useless in practice. This surely is an odd situation, particularly when we find that intelligence testing has attracted much political hostility—Hitler banned it because it was Jewish, Stalin because it was bourgeois. (They banned Einstein’s relativity theory for the same reasons!)

What are the main criticisms and questions you can hear over and over again in the media? One frequent assertion is that psychologists can’t agree on the nature of intelligence, and thus obviously have no idea what it actually is. Another assertion maintains that IQ tests have no practical importance, and measure nothing but the ability to do IQ tests. A third assertion is that the notion that IQ differences are largely due to genetic causes has been conclusively disproved since certain results reported by Sir Cyril Burt have been suggested to have been fraudulent. A fourth assertion states that IQ testing was invented to maintain the “status quo,” favouring the ruling class, and helping to suppress the working class. And as a fifth and final assertion we have the notion that IQ testing is a tool of racists to demonstrate the superiority of the white race. These five assertions have achieved great popularity among the uninformed; they share one characteristic in common—they are all completely false. I shall discuss them all in detail in due course, but will begin by briefly discussing each in turn.

1. Psychologists disagree about the nature and definition of intelligence

In 1988, Mark Snyderman and Stanley Rothman published a book, The IQ Controversy, which contained the answers of over 600 experts in the fields of intelligence testing, educational psychology, developmental psychology, behavioural genetics, sociology and education, cognitive science, counselling psychology, and occupational psychology to questions about intelligence, 99.3 percent agreed on the importance of abstract thinking and reasoning; 97.7 percent on problem-solving ability, and 96.0 percent on the capacity to acquire knowledge. This does not suggest a lack of agreement, and indeed these definitions agree well with common sense—we tend to call somebody intelligent who can reason clearly, think well in abstract terms, solve mental problems, and learn rapidly. Why then the notion that psychologists disagree?

Psychologists often describe the many things a high IQ enables us to do. These are indeed manifold, but to concentrate on one or the other does not imply disagreement on the nature of intelligence itself. Physicists may study many different consequences of gravitation—the apple falling on Newton’s head, the globular shape of the planets, the creation of the galaxies, the movements of the planets, the occurrence of tides, the existence of black holes, the laws of gunnery. This does not mean that physicians are in disagreement on the fundamental law of gravitation. Similarly, many different consequences can be deduced from the postulation of a factor of general intelligence, but that does not imply disagreement on its nature. There are of course debates about important aspects of intelligence, but then so are there debates about the nature of gravitation—is it a distortion of Einstein’s space-time continuum, is it a question of particle interaction, “gravitons” as quantum mechanics would have it, or what? Complete agreement on everything is not necessary to make a concept meaningful.

2. IQ tests measure nothing important, merely the ability to do IQ tests

Nobody who has even the most passing acquaintance with IQ testing would ever make such an outrageous statement. To take just one or two examples: IQ predicts with considerable precision a child’s scholastic achievement, or a youth’s success at university. In the famous Isle of Wight study, for instance, all five year olds on the island were IQ tested, that is, before they even went to school. Their final school grades at the age of sixteen years were predicted very accurately by their IQ, and when the IQ was reassessed at the same time, it had changed very little. In other words, IQ predicts achievement; it is not something you are taught at school. Similarly, IQ predicts success at university, law school, medical college, or indeed any advanced teaching unit more successfully than anything else, including interviews or special examinations. Within a given job, occupation or profession, IQ almost invariably correlates with performance. I will give more detail later, but it will already be obvious that IQ tests measure something very important indeed.

3. The notion that differences in IQ are largely determined by heredity has been disproved

Quite the contrary is true. It has been known for many years that heredity contributes more than environment to differences in IQ, but recent years have brought forth a veritable flood of evidence to support and strengthen this early finding. We have also experienced a tremendous improvement in the very complex statistical reasoning and modelling underlying any estimate of the relative weights to be given to nature and nurture, and we now understand much better than before just what it means to say that IQ differences are largely genetic, and what consequences follow from such a statement. Much of the criticism heaped on psychologists stating the simple facts of genetic determination derives from a completely erroneous perception of just what such a statement means, and what its consequences are. A major purpose of this book is to spell out these consequences in some detail.

4. IQ testing was invented to maintain the “status quo,” and strengthen the ruling classes

Such a statement is not only untrue, but contrary to the facts. In the first place there is no way in which IQ could be said to maintain the “status quo”; by identifying bright working-class boys and girls, and pushing them up the educational ladder, IQ testing leads towards a meritocracy, that is, a state of affairs in which leadership positions and access to the professions depends on ability, not nepotism, family connections, or whom you know. It is the great leveller that disregards feudal claims, parental status, and family influences. It was introduced originally precisely in order to enable bright working-class youths to obtain an education suitable to their talents, and not to be held back by examinations that favoured the rich, attending the better class of school, and kept back the child coming from an inner-city school. I knew many of the pioneers who introduced these tests, and they were all outraged by the handicaps suffered by deprived children of the poor, and determined to do what they could to make the playing field more even. The evidence supports the view that they succeeded; many more working-class children achieved a better education when IQ tests played a part in selection.

5. IQ testing was introduced to bolster the claims of the white race to superiority

Tests are essentially colour-blind, and give an objective estimate of intellectual ability. If anyone fancied, or hoped, that they would prove the superiority of the white (Caucasian) race he would have been bitterly disappointed. The races showing the highest IQ are the mongoloid races—Japanese, Chinese, Korean; whites are certainly not at the top. The highest scores go to the Jews who probably should not be counted as a race but as a religious sect; nevertheless, it will hardly gratify racist groups to find Jews at the very pinnacle of intellectual achievement!

All these criticisms tend to have a political context, as one might have anticipated from the dislike expressed towards IQ testing by Hitler and Stalin, brothers-in-arms to ban any signs of objectivity from the political landscape. Modern writers who seek to castigate IQ testing often sail under the flag of Marxism; this would include people like Steven Rose, Leon Kamin, and R.L. Lewontin, whose book, Not in Our Genes, received much favourable attention from journalistic reviewers in the media, and severe criticism from experts writing in scientific journals. The same was true of Stephen Jay Gould, whose book, The Mismeasure of Man, has more factual errors per page than any book I have ever read. Actually these writers, and many others who had added their voices to the Marxist choir, have not even been able to quote Marx and Lenin accurately. Here is a definitive statement from Lenin that should clear the air: “When one says that experience and reason testify that men are not equal, then one understands under equality the equality of abilities or the equivalence of bodily strength and mental capacities of men. It is quite obvious that in this sense men are not equal. No single reasonable man and no single socialist ever forgets this.”

Lenin goes on to characterize as an “absurdity” the idea of extending equality into these spheres and concludes by saying, “When socialists speak of equality, they understand thereby social equality, the equality of social position, but not at all the equality of physical and mental abilities of individual persons.” Even the Communist Manifesto asks “from each according to his abilities,” postulating differential abilities even after the communist heaven has been achieved!

I will not deal with political arguments any further. I am a scientist, not a politician, and while it is obvious that scientific findings may have social and political implications, these are never apparent, and the uses made of scientific findings depend more on one’s value system than on the facts discovered. When you find that a given person, or group of persons, has a low IQ, you may say, “Let them sink to the bottom where they belong,” or you may say, “Let us do whatever we can to allow them to develop whatever gifts they have to the utmost of their ability.” Facts are objective, decisions subjective. We may not like the facts, but they are stubborn; facts are the products of nature, and scientists are merely the messengers who seek and pass on the messages nature has for us. Don’t shoot the messenger, he is doing his best!

The notion is quite popular that the concept of “intelligence” is very modern and was invented by psychologists less than 100 years ago. It is also often said to be purely Western, and geared to capitalist economics. But of course intellegentia was used by the ancient Romans in much the same way we use the term “intelligence,” and even earlier the Chinese elaborated ideas about intelligence that are very similar to our own most modern views. Thus almost 2,500 years ago this concept was clearly defined by Confucius. He and his followers regarded it as being related to having a “top brain” and a quick mind, a reference to speed of mental functioning that we shall find amply supported by the most recent experimental studies. He also emphasized sensory discrimination, that is, the quality of eyes and ears to take in information, and use it to discriminate between different precepts. Again, the idea was used by Charles Spearman in 1904 to construct tests of intelligence which later work showed to correlate quite well with IQ tests. Confucius categorized people into three types: superior, medium, or inferior—“as stupid as two spring worms,” as the Chinese put it. This classification, of course, reminds us of Plato’s men of gold, of silver, and of brass, again referring to differences in mental ability.

Confucius laid it down that all people should be taught regardless of their ability, but type of education should be according to their ability. This again agrees well with modern achievement doctrines, as does his distinction between general ability and specific abilities, which we shall come across later on in its modern form. Finally, Confucius made the distinction between tian zi, the mental ability given by heaven, and shuan chang, the result of learning through training and education, an adumbration of theories of nature and nurture. The Chinese had no doubt about the importance of heredity in this context. They phrased this notion in terms of intelligence being a “gift from heaven”; thus an intelligent person is described as being de thian du hou, meaning “getting a uniquely big share from heaven.”

It would be equally wrong to imagine that intelligence tests are of modern vintage. Over one thousand years ago, the Chinese elaborated a test called the “Seven Coincidence Boards,” or wisdom boards; these closely resemble the Form Boards used in modern nonverbal intelligence tests. The wisdom boards can be manipulated to form a variety of figures, as shown in figure 1.1, thus testing visuo-spatial perception, divergent thinking, and creativity, although of course they did not form part of a psychometrically tested, explicit theory of mental ability. But implicitly China relied for 2,000 years on a civil service selected objectively by means of examinations open to all, and almost certainly correlating quite highly with IQ, this produced the longest period of existence for any civilized society the world has ever known, and also led to the discovery of many scientific and technical facts and inventions thousands of years before Europe was able to emulate the Chinese sages. As these few lines show, this tendency to outpace Europeans in scientific discovery extends even to the field of intelligence; here too the Chinese have anticipated most of our theories and practices, but as in physics, chemistry, medicine and astronomy, without putting their findings into an explicit theoretical context, or elaborating them into a properly organized practice.

Before going into detail about IQ measurement, it may be useful to say a few words about the concept of intelligence, if only because it is often used in different ways by different people, or even by the same person in different contexts, and this often causes confusion. One might even say that most of the confusion that is often apparent in public debates is due to simple misunderstandings that could easily be avoided with a little care. Let us start with a historical note. Our term “intelligence” comes from two Latin words: intellegentia and ingenium. The former, when you consider the ways Cicero used the term, means something like “understanding” and “knowledge”; the latter “natural disposition” or “ability.” These are two meanings of our term, intelligence, that have always adhered to it. Fundamental to intelligent behaviour is an underlying disposition that enables us to reason, to think abstractly, to learn. The greater this ability, the more we are likely to learn, and to know. This knowledge is thus itself a sign of high intelligence, although in a sense derivative. Raymond Cattell, one of the famous names in intelligence research, labelled these two aspects of intelligence “fluid” and “crystallized ability.” “Fluid ability” refers to the dispositional concept, the ability to acquire many kinds of knowledge. “Crystallized ability” refers to the knowledge already gained. Scientists will recognize the same sort of difference as that between potential and kinetic energy. Fluid ability is often written g_f, crystallized ability g_c, where g refers to general intelligence.

Figure 1.1 Chinese Seven Coincidence Board (wisdom board)

Nine-hundred-year-old intelligence test used in China. The task is to use the seven pieces in (a) to construct meaningful figures, as in (b) and (c).

These two aspects of intelligence are of course closely related. A vocabulary test is one of the best measures of intelligence because it is obviously a test of g_c, the number of words acquired by listening and reading is a function of g_f provided the environment contains a sufficient supply of spoken and written words. Tests of g_f contain no material that would not be familiar to everyone of a given age; the problem in each case cannot be solved by acquired knowledge. For example, the sequence of numbers:

2 4 7 11 16 ?

obviously requires for an answer the number 22, but this has to be worked out. The elements, simple numbers, are known to everyone. Of course this is a very simple test of g_p but it will illustrate the point. Even tests like this demand some small amount of knowledge, and if that is not forthcoming the test will be me...

Table of contents

• Cover Page
• Half title
• copy
• fmchapter
• 1 The Paradox of Intelligence and Its Measurement
• 2 Origin and Meaning of the IQ
• 3 Nature and Nurture: The Great Partnership
• 4 Intelligence, Reaction Time, and Inspection Time
• 5 The Biological Basis of Intelligence
• 6 What is the Use of IQ Tests?
• 7 Can We Improve IQ?
• 8 Many Intelligences?
• 9 Creativity in History—What is Genius?
• 10 Creativity and Intelligence
• 11 Conditions for Excellence and Achievement
• 12 Genius and Heredity
• 13 Psychopathology and Creativity
• 14 Cognition and Creativity
• 15 Much Ado about IQ
• Endnotes, References, and Comments