How much can man change and at what age is it too late to hope for very much change? It has been important that we know, but we had no means of doing so. Now thanks to Professor Bloom’s study of Stability and Change in Human Characteristics we do know, and the implications for social planning are vast indeed.

The dialectic process never stops. Only recently has American social science adopted the psychoanalytic view of man; hence the widespread conviction that human personality is shaped in infancy, and that the early characteristics are extremely resistant to change. Nevertheless, we find our social scene flooded with statements on how this or that form of social engineering is going to change personality at an age when (according to psychoanalytic theory) personality can hardly be changed short of long-term therapy or some influence of equal depth.

If it is not already plain, I am speaking, among other things, about the present controversy over school integration. Mixing children of different backgrounds is supposed to change the outlook on life of the culturally deprived child and to improve his academic progress, as if both were not determined before he entered kindergarten or first grade. We are told that the attitude toward learning is such a superficial characteristic that it depends merely on what happens in class, or with whom one goes to school. Often the same social scientist who believes on the one hand that infant rearing shapes personality claims on the other that the intellectual virtues are superficial enough to be conditioned by chance experiences in class. But, in fact, psychoanalytic theory holds that the attitudes formed in infancy are what condition the classroom experience.

More recent revisions of psychoanalytic theory deny that the basic personality, on which the child’s view of learning depends, is essentially formed with the resolution of the Oedipus complex. According to the most important revision of the Freudian system, that of Erik Erikson, basic trust is the ground rock of all later trust in others (including one’s teachers) and in oneself (so vital in attacking problems) and depends on the very earliest experiences of life. If these have not been favorable, they may condition, inversely, a life-long distrust of others (including one’s teachers and what they teach) and of oneself. As if this were not bad enough, our autonomy—including the qualities required to attack intellectual problems—depends on experiences we have only slightly later in life, and so does our ability to take initiative in meeting problems. When school age finally comes, it is the combination of trust, autonomy, and initiative that will condition whether or not we are capable of the industry so important for learning. Conversely, if our pre-school experience has bred mistrust, shame, doubt, or guilt into the personality, the school experience will reflect not industry, but inferiority.

If Erikson is correct, then the school experience of one kind of child will stand under the triad of trust, initiative, and industry, characteristics which will send an intelligent child brought up in good cultural circumstances to the head of the class no matter what. The school experience of another child will stand under that other triad of mistrust, shame, and doubt, and will lead to inferiority. Every experienced teacher knows that if these qualities are present, even in fairly pure culture, paired with good intelligence, they will make learning and teaching impossible. They are what characterize the personality of the non-learner or, in milder form, the under-achiever. They are the characteristics found dominant in children from culturally deprived homes or disadvantaged ones. True, they are also found in children from very different homes, but such children are exceptions; among children from deprived homes, these characterics are endemic.

If these theories on human development are correct, and if the characistics most needed for school achievement are those stated, no Supreme Court dictum saying that academic achievement depends on how children are grouped in school can help. The facts of human nature cannot be changed by a court dictum; not, at least, without our also creating conditions that would allow it to be effective.

But suppose these theories are not valid. Suppose that how a child fares in school does not depend on his personality, but on what happens to him there. Perhaps these issues are too important for decisions about them to be based on psychoanalytic theories. Once more we confront the sterile controversy of nature versus nurture: Is man the result of his environment or his inheritance?—but with the difference that inheritance has been largely replaced by early experience. Thus today’s controversy seems to center on the question: Is man the result of his earliest or his later experiences? Or to put it within the context at hand, is human personality and achievement the result of pre-school or in-school experience? Whether we can expect different schooling to matter much or little will depend on how this controversy is resolved.


If we decide that different schooling will matter little, we may still wish to press for integrated schools as a matter of social justice, but this will not help the child coming from a disadvantaged home to lift himself out of his dreary background. We must recognize that as far as helping the socially and culturally deprived is concerned, the fight for integrated schools is a kind of shadow boxing which obscures the fact that we fail to do the social engineering where it counts, during the first few years of life. Of course, if we decide that we can radically change central aspects of the personality after age six by simply giving the child a different school experience, then we must concentrate our social engineering there, and can forget about the earliest years of life. If so, we shall also have to scrap the psychoanalytic theory of personality, because it has misled us with its claim of the vast importance of earliest experience. Here the two arch enemies, psychoanalysis and the Catholic Church, see eye to eye. Witness the Jesuits’ conviction that if they are given the child up to the age of seven, they do not fear for the child’s future development.

There have been some straws in the wind suggesting that both the Jesuits and, several centuries later, the psychoanalysts were right. For example, studies of children who achieved differently in reading reveal that success, or the lack of it, depended on the attitudes they brought with them to school. If on entering school they thought of themselves as readers, were convinced of the value of reading, convinced that they could learn to read easily (that is, had trust in themselves and initiative in tackling learning), then they had an easy time learning to read. Those who came to school doubting the value of reading, and doubting that they could learn to read, failed by and large, even though they shared the same classrooms and were exposed to the same stimulation. The identical setting gave them an experience exactly opposite to what the good learners had.

Still, this was merely a straw in the wind. What was needed was greater certainty, more precise evidence that would stand up under the most careful scientific scrutiny. In matters of such complexity, bearing so crucially on what is today the greatest issue in the nation, such evidence was a great deal to expect. But it has now been provided in Professor Bloom’s scholarly book. Because it is a technical study with many statistical graphs, tables, and charts, it is to be feared that it may be less widely read than it deserves to be. That it is a statistical study may make it forbidding reading to some, but it cannot be overlooked by anyone concerned with education. Those who cannot follow the intricacies of statistical analysis will still be richly rewarded by the eminently readable text. For the substantive findings and the marvelously thorough analysis of this study have tremendous implications for our social and educational planning.

Benjamin Bloom brings the highest credentials to his task. He is Professor of Education at the University of Chicago and was for many years its university examiner. A life-long student of educational achievement and its evaluation, he is currently President of the Association for Educational Research and a member of the standing committee of the International Study of Educational Achievement. In his book he surveys and synthesizes the findings of all major longitudinal studies of youngsters, some of which have followed particular children for ten or more years, and compares them with other relevant research on human intelligence and achievement. His methods allow him to answer questions like the following: Under which conditions can human development be altered and how do different environmental conditions affect the growth and development of human characteristics? How much can environmental forces affect the development of a characteristic, and what are the limits for affecting a characteristic by educational or other environmental forces.

Though none of the longitudinal studies which are analyzed in this book were based on psychoanalytic thinking, Professor Bloom finds that characteristics acquired early in life are the most stable of all, thus corroborating psychoanalysts’ hypotheses on the importance of the first years of life. No other study, based on highly objective data and subjected to the most rigorous statistical analysis, has so powerfully supported the speculations of Freud and his followers. More than this, Professor Bloom shows that characteristics developed in a short time are not very stable, which suggests that we should be dubious of stories describing far-reaching changes in human characteristics that are achieved within months. He too finds what psychoanalysis has taught us: that while the basic characteristics are very stable, the symptoms that express them are not. Yet despite these conclusions we still direct most of our social engineering, in problems like juvenile delinquency, school drop-outs, etc., toward changing the symptoms instead of the characteristics behind them.


Probably the broadest implications of Professor Bloom’s findings are those bearing on intelligence and academic achievement. His analysis of studies of identical twins shows that when children are brought up from shortly after birth in radically different environments, their intelligence varies markedly. If one twin was reared in an environment that was highly nutritive to both his intelligence and his emotional life, and the other grew up in an opposite kind of environment, then their I.Q.s varied at maturity by as much as twenty points. As Bloom says, these twenty points.

…could mean the difference between a life in an institution for the feeble-minded or a productive life in society. It could mean the difference between a professional career and an occupation which is at the semi-skilled or unskilled level. A society which places great emphasis on verbal learning and rational problem solving and which greatly needs highly skilled and well-trained individuals to carry on political-social-economic functions in an increasingly complex world cannot ignore the enormous consequences of deprivation as it affects the development of general intelligence.

On the surface, this seems to be an argument for the impact of environment on intelligence as voiced by those who say children should be shifted from one school to another to improve their academic achievement. But the shift in schools does not help much because it appears that only during the first four years of life does the I.Q. change markedly with environment—up to two-and-a-half points per year. From ages eight to seventeen (school age) the highest average effect that even the most radical change in environment produces is not more than O.4 I.Q. points per year. In ten years this does not exceed a change of four I.Q. points, far too little to make a real difference. The conclusion must be that though it is tremendously important to provide infants with the most favorable environment during the first four years of their lives, the influence of the environment on intelligence becomes smaller and smaller with each year after the fourth, and by school age is insignificant.

Equally crucial is the research that compares children, born and raised in Philadelphia, who maintained about the same I.Q. score throughout grade school, and their Negro classmates, who were born in the South and moved to Philadelphia at different ages. If school integration pays off in change of intelligence, the scores of the Negro children should have improved with their move to these schools. But the only real improvement was made by children who changed their environment before school age, those who moved to Philadelphia before six. These children gained an average of six-and-a-half I.Q. points during the first to ninth grades, showing the cumulative effect of more favorable conditions and a more intellectually nutritive environment. Unfortunately, a change of six-and-a-half points in I.Q. though quite marked, has little practical effect. An improvement of twenty points, on the other hand, can make a tremendous difference. Such an improvement seems to be impossible, however, unless the change in environment is made soon after birth, since half of this gain (ten points) would have to be made during the first four years of life. Even the six-and-a-half points were gained only by children who moved to a better environment long before school age. Children who were born in the South and moved to Philadelphia when they were in the fourth grade gained only about three I.Q. points during the rest of their school career, while children who did not come till the sixth grade gained only two I.Q. points. Thus we see a marked decrease in the effect of better environment as children grow older: The greatest changes happen during the first few years of life, and the next greatest during the first few years in the new environment.

This is true of all children, not only those who move from a culturally deprived environment to a better one. In analyzing all research on developing intelligence, Professor Bloom found that half of all the growth in intelligence takes place between birth and age four. The next 30 per cent increase in intelligence is made between the ages of four and eight. Between eight and seventeen, when the child is of school age, intelligence increases only about 20 per cent. In short, just as much intelligence develops in the first four years of life as in the next thirteen years, and there is very little growth after eighteen.

What are the specific factors in an environment that have so much influence on the growth of intelligence? Professor Bloom and his co-workers identified thirteen such factors, all relating to family background or to the relations between parents and children. Seven of these factors are process variables indicative of the parents’ response to the child and his capacities—their intellectual aspirations for him, the rewards they offer for intellectual growth, the opportunities they provide for learning inside and outside the home (not including school); and the nature and amount of help they give to extend learning in a wide variety of situations. The other six factors tend to be more stable: they are characteristics of the parents and the home. Among them are the parents use of language in a variety of situations; the opportunities in the home for enlarging vocabulary and the quality of the language used; whether there is emphasis on correct use of language; the availability of books, periodicals, and library facilities. These thirteen factors account for two-thirds of all intelligence development, a process that is completed before the child even enters school. Thus if we were really serious about doing something for the intellectual development of underprivileged children, we would have to make our influence felt in their homes by encouraging parents to change their intellectual expectations and aspirations for their children as well as their own language habits, and to make learning supplies, periodicals, and books available.

So much for the intelligence we suppose to be inborn. What about achievement in school? Even for general achievement, such as reading comprehension, the ground is laid long before the child enters school. A full third of whatever the child will achieve later in school is developed by the time he gets there, probably because so much of it depends on vocabulary development and language comprehension.

The home environment is very significant not only because of the large amount of educational growth which has already taken place before the child enters the first grade but also because of the influence of the home during the elementary school period.

By the time the child has reached an age when the home influence is waning, when he is old enough to strike out on his own—that is, by the end of grade school—a full 75 per cent of all his academic achievement has already been made. Thus efforts in behalf of the child after that time can only influence 25 per cent of his total academic achievement. In other words, if we could stimulate a student to do 20 per cent better in high school (a tremendous gain, if achieved), it would improve his overall achievement only 5 per cent, a rather insignificant gain.

The home environment not only conditions the level of achievement the child reaches when he enters school, but continues as a powerful influence no matter what his school experience. Children coming from different homes were matched in respect to their reading achievement at second grade. When they were retested at the eighth grade, the children with fathers in occupations requiring higher education were on the average 2.25 grade levels ahead of those whose fathers’ occupations required less than a high school education. Thus even if children go to the same type of school and start out in second grade at the same level of achievement, whether or not the home supports the school’s educational efforts will make all the difference in the child’s final achievement.

Besides the implications for educational planning, this study also contains much fascinating information on the incredible stability of early acquired human characteristics. For example, whether and to what degree a boy will be aggressive (so important a factor in juvenile delinquency, to mention only one consideration) is more or less set when he is three, for by this time he has reached the half-way mark in the development of this characteristic. The inversely corresponding characteristic of dependence reaches its half-way mark in girls by the age of four. This is also true of both general intelligence in boys and girls, as I have noted earlier, and for the equally important characteristic of intellectuality.

Why then are we so blind to the fact that all our educational planning for the underprivileged beings when for all practical purposes it is too late? And this despite all that psychoanalysis has taught us. One answer is that so few psychoanalysts are interested in or knowledgeable about education, and that they concentrate their interest on the development of the emotions, not the intellect. But there is another answer, as Professor Bloom points out.

The prolongation of the period of dependency for youth in the Western cultures has undoubtedly been a factor in desensitizing parents, school workers, and behavior scientists to the full importance of the very early environmental and experiential influences.

By keeping youth in school so many years we have made ourselves believe that added years of schooling will make a difference: Witness the present efforts to keep dropouts in school, as if at sixteen one or two more years in school could influence their intelligence or academic achievement.

But while we try to add more schooling at the end, “a central finding in this work is that for selected characteristics [intelligence, academic achievement, aggression, etc.] there is a negatively accelerated curve of development which reaches its midpoint before age five. We have reasoned that the environment would have its greatest effect on a characteristic during the period of its most rapid development.” This means that if we want to raise the intelligence of children by the possible maximum of twenty I.Q. points (the rest of their intelligence is conditioned by inheritance) we must change their environment long before they come of school age. To do this we will have to free ourselves of a few of our most widely held prejudices—that the child is the private property of his parents to do with as they please, that we are therefore powerless to change the environment he grows up in, and that human beings are infinitely improvable, at any age, no matter what the home environment of their childhood. Or, in the unemotional language of the scholar who wrote this book:

There appears to be an implicit assumption running through the culture that change in behavior and personality can take place at any age or stage in development and that the developments at one age or stage are not more significant than those which take place at another.

Will we heed the advice implied in this remark? Will we base our planning for all children, privileged or not, on the unassailable facts he presents? If so, there must be radical reform in the lives of children between the ages of two to four or five. Or will we continue to fool ourselves by thinking that we can change the lives of underprivileged children in school, when it is much too late for everything that really counts? I believe that reform must be concentrated where it most matters—on the conditions of life at home—if we are to give these children what they most need.

This Issue

September 10, 1964