Man, so we are told, has achieved his present evolutionary status because of his intelligence. Prehistoric man was "backward", relatively speaking, because he lacked intelligence. In a similar vein, we are often asked to believe that the successful members of society are the intelligent ones, whereas the failures and dropouts are in some way deficient. What is this desirable quality that makes us what we are and enables us to achieve varying degrees of success in the world?

To begin with, the term
intelligence itself is often used as if it referred to some objective substance of the mind---something definite which people can have more or less of. Of course, no one wants to claim that intelligence is located in a particular part in the body. Intelligence is more like a skill than an object. Just as possession of a muscle does not guarantee effective use of that muscle, so knowledge must be carefully analysed and coordinated if it is to be used intelligently. Intelligence is not simply the ability to store facts. It requires an intelligent mind to store and use facts appropriately in a particular situation. At this level of generality a definition of intelligence presents no serious problems. But when we try to specify exact behaviours that could be said to be intelligent or to define precisely the skills and processes that make up intelligence we immediately run into difficulties.
For centuries, philosophers have grappled with the problem of intelligence. A multitude of definitions has been offered ranging from an ability to think creatively to an ability to do well on intelligence tests. We're quite clear that intelligence has something to do with thinking. But, unfortunately, this insight is not very helpful as we are equally unclear as to what is involved in thinking. There's no doubt that some people are more intelligent than others. For example, adults are generally clever than children (although not always, in all things). But we are unsure why. We can only point to problems that adults can solve but which children cannot. For example, present a five-year-old child with two sticks, A and B, and ask him which is the longer. He will correctly answer A. Next, present him with a further two sticks, B and C, of unequal length and repeat the question. He correctly answers B. Finally, asking which of A and C is the longer. Chances are that he will answer incorrectly. Yet to the great majority of adults, the correct answer is both necessary and obvious.

Tests like these abound in the psychologist's bag of tricks. They certainly relate to our intuitions about intelligence but they tell us very little about what intelligence is or how it is acquired. Most tests are designed to investigate a particular aspect of intelligence. Thus, given that different psychologists view intelligence in different ways, the tests vary accordingly.
In this chapter, some attempt will be made to convey the flavour of the different approaches that psychologists and philosophers have offered to the problem of intelligence and how children acquire it. There are three approaches that can be distinguished: that of the nativist, the empiricist and the interactionist. Each theory has its own historical origins which can be traced back to Plato, Locke and Rousseau, respectively. In some cases, the geographical roots also reveal surprising coincidences. Piaget, the modern day father of interactionism, was born and raised in the environs of Geneva–Rousseau's native home. While behaviourism, which has a strong tradition in Britain and America, has its derivation in the School of British Empiricism founded by Locke.

Coincidences like these serve to remind us that individuals have been working on similar problems for centuries, each following their own particular cultural tradition. Unsurprisingly, the nature of the answers themselves have not changed fundamentally. We hope to show in the remainder of this chapter that the detailed knowledge psychologists have acquired over the past 10 or 20 years is, however, bringing us close to the point where the age-old controversy of intelligence may be resolved. To anticipate a little, none of the established theories appear to be entirely accurate. Each provides a certain insight that improves our understanding. Our task is to recognise the bounds of particular theoretical perspectives.

The Nativisit View

Plato believed that by selective breeding it would be possible to produce an elite group of highly intelligent people to govern his ideal state. More recently, some psychologists suggested that children are born with a certain quota of intelligence which sets limits on their potential for intellectual achievement. Furthermore, this intelligence quota is determined by genetic means, i.e. the IQ of a child is largely governed by the unique interaction of his parents genes. Broadly speaking, this implies that intelligent parents will produce intelligent children were less able parents will produce less able children. Intelligence is viewed as a capacity that is passed down from one generation to the next. As it stands this claim is indisputable-our capacity to think and reason is a capacity inherited from our ancestors as much as our ability to walk or see. But, the nativists claim, the transfer of intelligence from one generation to the next is no mere social process. It is biologically determined. The social environment can only help the individual achieve his innate, intellectual potential. It cannot take him beyond this limit.

Notice that the nativists provide no precise definition of intelligence. Their major concern has been to substantiate the wider philosophical claim that human skills, which intelligence is but one example, are biologically inherited. To be fair, most nativists that distinguish various forms of intelligence-for example verbal and spatial skills.
These distinctions are only realised in the different types of tests that are administered to measure the different skills. No precise definitions of these different forms of intelligence are provided.

The normal procedure of an intelligence tester in this tradition is the use of standardised IQ tests. Standardised implies that the test, which consists of a variety of problems, has been administered to a large number of children from a similar socio-economic background. The test is adjusted so that the distribution of scores obtained with the greatest number of children scoring in the mid range of the distribution. Thus a typical child from an average white middle class background can expect to score 100. as we go up or down the scale from this point we will find fewer and fewer children.

An important point to remember is that an IQ score is not an absolute measure. Through the test's standardisation, a child's score is relative to what other children, from a broadly similar background, may expect to score. There are two problems with this procedure. First, the test may be inappropriate for a particular child because his background is very different from those on whom the test was standardised. To take an extreme example, one African tribe is unaccustomed to perspective cues in line drawings. Any tests which incorporate these features would be an inappropriate measure of this tribe's intellectual capacity.
For this reason, IQ tests must be able to take into account the cultural background of the person tested. Culture free tests have been invented for just this purpose. However, a second objection to IQ tests, but the culture free or culture specific, is that they are unable to capture the wide variety of skills that children are likely to possess. Each child has a unique experience of the world, an experience which enables him to develop a unique combination of talents. In a sense, he is a walking mini culture. No test is able to capture this kaleidoscopic variety. Consequently, no test can tap and hence measure the variety of intellectual skills that the child almost certainly brings to the testing situation. The American linguist, William Labov (1970), can precisely this limitation of conventional tests when attempting to assess the verbal skills of black children in New York. However, he found that if he got to know the children, allowed them to bring a friend along and sat down on the floor to talk with them, then the black child from Harlem shows that he is sophisticated speaker from a background where verbal skills are valued highly.

The IQ test can at best give us as crude indication of a child's intellectual skills which are certain culture, or certain psychologist, values. At worst, the IQ test provides a gross distortion of the child's skills, completely ignoring the complex abilities he has almost certainly developed for other tasks.
In this context, consider the case of the nativist's innateness hypothesis, which relies on the results of IQ tests for its claims to be substantiated. For the nativist, the crucial test is whether a child's IQ profile is similar to that of his biological parents. Matching profiles that supposedly constitutes support for the theory. Very often, significant correlations are found between a child's IQ and that of his parents. Intelligence, it would appear, is biologically inherited. However, given the crudity of IQ tests, it is unlikely that tests administered to adults are measuring the same skills as those administered to children. Even if the tests compared include those of the parents themselves when they were children, the 20 or 30 years between the different test administrations can be confounded by radical changes in social and intellectual climates. From where then does the significantly correlated IQs between parent and child appear?

This brings us to our second objection to the nativist's conclusion. Any parent will provide for their child a special environment for development. Normally, the environment will be sufficiently rich for the child to exercise a wide range of skills-verbal, spatial, perceptual, motor et cetera. At the same time, this environment places limits on the child's opportunity for growth. Even an innate skill requires a suitable environment for it to function adequately. To a considerable extent, the constraints on the child's opportunities are associated with the parent-the parent's job, the family's economic position, the degree to which they
play with the child, the parent's attitude as to what is important in child development. All these and more are crucial determining social factors in the development of the child's intellectual skills. Furthermore, these social determinants have been acquired by the parents themselves in their own development. Many sociological studies repeatedly point to reproduction of lifestyles within families from one generation to the next, even to the extent that father and son are often found in similar types of employment. It is small wonder then that children say equally well as their parents when asked to perform an IQ test. The attitudes and opportunities for the development of skills are likely to be very similar. We need not invoke some mystical inherited quality to explain these results-just look at the way people live!

Most psychologists are aware of these problems and have sought to carry out investigations that might overcome the objections. The most convincing account from the nativist camp concerns the study of identical twins (i.e. individuals possessing identical genetic inheritance).

It is generally agreed amongst proponents of this approach that 80% of an individual's intellectual capacity is determined by heredity while only 20% of the variation between individuals is determined by the environment. On this basis, identical twins should exhibit an overwhelming similarity in intellectual skills irrespective of their
background. In particular, identical twins reared apart show greater similarity in intelligence than nonidentical twins reared together, given the overwhelming influence of inheritance as compared to environment. In a lengthy series of studies, Sir Cyril Burt (Burt and Howard, 1957) put forward data supporting precisely this position. More recently, however, Leon Kamin (1974), in a careful reanalysis of Burt's results, revealed a number of contradictions in the data suggesting that the investigation had not been as objective as one expects of scientific enquiry. This is, of course, is not sufficient to discredit all such evidence, but it does indicate a tendency to stress one point of view, without giving adequate weight to the alternative factors. The main criticism of twin studies with that investigators were paid insufficient attention to the phenomenon of selective placement, i.e. the tendency of adoption or fostering agencies to put separated twins in the homes of similar quality, thereby diminishing the range of environmental effects.

The Empiricist View

In contrast to the nativist's view of intelligence as an inherited quality, biologically transmitted from one generation to the next, the empiricist emphasises the role of the environment, both physical and social, in the reproduction of man's intellectual qualities from one generation to the next. The most extreme proponents of this approach see the human newborn as a "tabula rasa" will
blank slate upon which experience is written. The infant brings to the learning situation is nothing other than the body he is born with. No mental pre-programming exists. However, the empiricists go further than denying that intelligence is an innate, genetic quality. They also attempt to provide a precise definition of intelligence. This definition has realised its most articulate form in the behaviourist school of thought-the modern day counterpart of the empiricist tradition.

Intelligence for the behaviourists is founded on the simple but crucial ability of living organisms to associate one event with another. The most celebrated examples of this ability are Pavlov's dogs. The Russian scientist, IP Pavlov, demonstrated that a dog could learn to associate the sound of a bell with the subsequent presentation of food. After repeatedly ringing a bell when the dog was fed, Pavlov found that the bell alone would elicit the same response as the food, namely, salivation. The dog had learnt that the bell signalled food. This process is known as classical conditioning. Notice that the learning process is beyond the control of the animal. It's only contribution is to associate the events-bell and food-which occur in the environment. Pavlov also discovered that a further signal could be conditioned to the already conditioned bell. For example, by presenting a flashing light immediately prior to ringing the bell, the light will come to elicit salivation. In other words, chains of associations can be created.

Since Pavlov's famous experiments, many psychologists have demonstrated that humans can be conditioned in a similar way. If a puff of air is directed at the eyes, our automatic response is to blink. However, we can "persuade" someone to blink to a buzzer if we so wish. By pairing the buzzer with the puff of air a number of times, the buzzer will come to elicit blinking when presented alone. Even young babies can learn to make these associations. Here we see a form of "intelligent" behaviour-the capacity to predict one event on the basis of another and respond appropriately. Hardline behaviourists would claim that this is all there is to intelligence-knowing what to do and when to do it. Supplement the single association with the ability to build up chains of responses and we have a theory that can account for the most diverse feats of learning imaginable.

Intelligence comes from the environment because it is determined by the co-occurrence of events in that environment. All the infant supplies is the ability to associate those events. Our ability to learn is governed by the environment. In this respect, the empiricist's view of intelligence is more optimistic than the nativist's: we can improve our intellectual capacity by changing the environment in which we live. In contrast, nativists would shackle us to our preordained quota of intelligence which no amount of environmental enrichment can alter.
The assumption of the behaviourist theory of intelligence, that intelligence is a network of mental associations, is also the foundation of its weakness. Intelligent behaviour emerges, so we are told, when an unrelated environmental event comes to elicit the response in the organism that another event would normally trigger. That is, the empiricist view of intelligence requires the existence of an already wired in set of reflexes on the part of the child if he is to get started on his intellectual development. The child cannot learn to respond to an unrelated event if he doesn't already know how to respond to the related event. Put simply, the child can't be conditioned to eye blink to a buzzer if he doesn't have the capacity to blink in the first place.

Clearly, the child's capacity for learning is constrained by the set of innate reflexes he brings into the world. No amount of classical conditioning will teach a child how to fly. The empiricist's "Tabula rasa" or blank slate, must be a myth if their own theory is to get off the ground. But even with this concession to innate predispositions, the empiricist theory offers a radically different alternative to the nativist's view of intelligence. The essence of intelligence is our capacity to build upon innate predispositions in response to environmental experiences.


The empiricist view of development is indeed optimistic. Given the innate reflex constraints of the neonate, there is in principle no limit to the conditioned reflexes that the child may learn. Any skill based on reflex chains should be acquirable from the very beginning of development. In contrast, common sense informs us that the opportunities for development are not as wide open as the empiricists would have us believe. Most infants appear strictly limited in their skills despite concerted adult attempts to train them. Admittedly, the common failure to train a diverse repertoire of abilities may be a consequence of inadequate training methods. However, the frequency of this failure suggests a more deep-seated limitation on child development.

The interactionist view of intelligence represents an attempt to identify the role of both the environment and innate abilities in development. However, it is no mere compromise of the empiricist position. The interaction seeks to demonstrate that development is structured, that there is an order in the manner a child acquires his intellectual and behavioural skills. The focus of the interactionist account is the point where innate or already developed skills come into conflict with the world. For it is here that the role of innate skills and the environment is most clearly seen.
Let us illustrate the argument with an example. A young child is playing with a foam board. Over the past year or so, he has been learning how to recognise different shapes and handle them in his grasp. His task now is to place the different pieces in the different shaped slots. We can speculate that children who succeed at this task do so because they construct a mental image of the shape in their hand and try to match this image to a slot on the board. The child selects an appropriate slot and attempts to position the shape. Sometimes he will succeed, and other times he will experience the frustration of failure. It is this latter predicament that interests us. If the child is to transform his failure into success other than by trial and error, he must modify the image he has constructed of the shape. For he has clearly failed because his image is inappropriate. We know that the ability to imagine the shape of objects has been developing over the past year. Yet the child has still to master the skill completely. It is in situations where the child's skills are inadequate to cope with the environment that the child begins to learn. The environment (in this case the form board) demands that the child changes the way he transforms an object into an image of its shape. Only then will the child be able to predict accurately the correct slot.

Intelligence than is the outcome of a dynamic interaction between performance skills and a stubborn environment which refuses to yield to the skills. The child develops when
his own abilities are inadequate for the situation at hand. To use a biological analogy, the child who cannot assimilate an environment must accommodate to its demands. We see in the interactionist approach elements of both the nativist and empiricist approaches. The innate, nativist skills enable the child to cope with the world while the empiricist's environmental demands force the child to develop his capacity to cope with the world.

We can now begin to understand why the interactionist demands that there should be order in a child's development. For all intents and purposes, every child enters this world with a similar set of innate skills. These are the abilities that enable the infant to consolidate his existence. Furthermore, the problems that the infant is posed by the environment are likely to be similar despite his social or economic status. The infant must learn to find the nipple and adjust to a varying supply milk. He must adjust his grip to accommodate different shaped objects. He must learn how to keep sight of moving objects by following them with his eyes. Each and every infant must learn a similar set of primitive skills if he is to survive. And these problems will place similar demands on the child's innate abilities. The very structure of the world forces a direction of development on the child. This direction cannot be haphazard because the infant must learn certain skills if he is to survive. The more specialised and esoteric skills can wait until later.
At this point, in an introductory chapter on intelligence, it would be conventional to provide a fairly detailed account of one interactionist theory of intellectual development, namely Piaget's. Piaget proposed a sophisticated and comprehensive account of child development from birth to adolescents. He argued that intellectual development is not a gradual continuous process goes through a series of radical stage like changes (four, to be precise). In each stage the child's way of looking at the world changes fundamentally. In short, his mode of interacting with the world becomes more and more abstract. These changes are the outcome of our innate skills grappling with the problems posed by the world. As our skills change, the kind of situations we can cope with change. But, in parallel, our horizons broaden and the one problem we have just solved is replaced by a multitude of others. The young child intellectual development is a continual process of coping. Not until he has attained a sufficiently sophisticated repertoire of skills-and that level depends on the society in which he lives-will he achieve a degree of equilibrium in his intellectual life.

We refrain from providing a detailed account of Piaget's theory for two reasons. First, the purpose of this chapter has been to contrast the different kinds of approaches towards intelligence psychologists have developed during the past century. Secondly, there are numerous introductions to Piaget's work already available. We refer the reader to the bibliography.
But as an example of Piaget's investigatory approach, consider the following problem. A six-year-old child is presented with a small bunch of flowers. There are three yellow flowers and six red flowers. He is asked family yellow flowers there are-he answers three. He is asked how many red flowers-he answers six. Finally, the child is posed the following problem. Are there more red flowers or more flowers? The child answers that there are more red flowers. The child's answer may seem "irrational" but six-year-old children really do make mistakes like these.

It is been a major contribution of the interactionist approach to uncover such "oddities" as these in the child's mental life. It has been the great triumph of interactionist thought to explain these apparent irrationalities within a single coherent and rational framework.