The Her It Ability of Intelligence ARTHUR R. JENSEN

THE SATURDAY EVENING POST

The Her it ability of Intelligence of l.Q.'s going from 90 to 110. l.Q. children in later adulthood markedly excelled ARTHUR R. JENSEN Significance of the LQ. the general population on every indicator of Can the LQ. tell us anything of practical im- achievement that was examined: a higher level of The question of why people differ in intelli- portance? Is it related to our commonsense education completed; more scholastic honors and gence bas been asked for centuries, but a scientifi- notions about mental ability as we ordinarily think awards; higher occupational status; higher income; cally acceptable answer did not become wholly of it in connection with educational and occupa- production of more articles, books, patents, and possible until psychologists devised techniques for tional performance? Yes, indeed, and there is no other signs of creativity; more entries in Who's measuring intelligence quantitatively and objec- doubt about it. The massive evidence from psy- Who: ii lower mortality rate; better physical and tively. The first really useful intelligence test was chological, educational and industrial research, mental health; and a lower divorce rate. Also, they devised in 1905 by the French psychologist Alfred and research in the armed forces, is unequivocal. have much brighter children than the average; their Binet. Binet's early test was later revised and im- We know, for example, that no other single fact average LQ. is 133, a level which is exceeded by proved by Lewis Terman at Stanford University; that we are now able to ascertain about a child only 2 percent of all the children in the general the now-famous test that resulted from these ef- gives us a better prediction ofhis future scholasfic population. forts is known as the Stanford-Binet Intelligence performance than his LQ. obtained after age 5 or Findings such as these establish beyond a doubt Scale. It is stiU the most widely used test of general 6. (Below this age LQ. tests become less accurate that LQ. tests measure characteristics that are intelligence. indicators of the child's later mental development, obviously of considerable importance in our pres- There are other intelligence tests, and although and below 2 or 3 years of age test scores have prac- ent technological society. To say that the kind of many of them appear to be quite different from tically no predictive value.) ability measured by intelligence tests is irrelevant one another, all actually measure much the same The LQ. obtained after 9 or 10 years of age also or unimportant would be tantamount to repudi- general ability. That is to say, if we administer predicts final adult occupational status to almost ating civilization as we know it. several seemingly quite different intelligence tests as high a degree as it predicts scholastic per- The Causes of LQ. Differences to a large number of persons, their scores on all the formance. When various occupations are ranked The layman usually asks: "Is intelligence due to tests will be in pretty much the same rank order. for average income and for the general public's heredity or environment?" The scientist promptly Those who score high on one test will tend to score average judgment of the occupation's prestige and answers: "Both." WitlKJut heredity and environ- high on the others, and those who score low on one desirability, this rank order is found to be highly ment there simply is no intelligence. Obviously test will usually score low on all the others. This related to the average LQ. level of the persons in every person must have had a biological inheri- fact of correlation among all tests of intelligence these occupations. There is of course a wide spread tance of genes from his parents and must have led Charles Spearman, the famous English psy- of l.Q.'s in nearly every occupation, but the aver- grown in an environment, or he wouldn't even be chologist, to conclude that there is a general fac- age LQ. of persons within a particular occupation here to take an LQ. test. So, of course, both hered- tor, "g," which is common to all tests of intelli- is closely related to that occupation's standing in gence. We know that it is practically impossible to ity and environment are essential for the exis- terms of its average income and the amount of tence of the individual or any of his physical and make up a mental test having any degree of com- prestige accorded to it by the general public. plexity which does not involve "g." We can per- mental characteristics. One of the most convincing demonstrations haps most clearly characterize "g" as an ability for But when scientists actually study this prob- that LQ. is related to "real life" indicators of abil- abstract reasoning and problem solving, for seeing lem, we find that they do not even ask the lay- ity was provided in a classic study by Terman and relationships, and for grasping concepts. man's question. The question to which scientists his associates at Stanford University. In the 192O's have sought an answer can be stated as follows: A person's score on an intelligence test is usu- they selected a total of 1,528 children with Stan- How much of the variation among persons in a ally expressed as an LQ. (for Intelligence Quo- ford-Binet l.Q.'s above 140. The average LQ. of given population is attributable to differences in tient). The test is standardized in the general popu- the group was 152. These children were investi- their environments and how much to differences lation in such a way that the average LQ. at any age gated periodically over the years up into their in their genetic endowments? adulthood. (Most of them are now in their fifties.) is set at IOO, and the middle 50 percent of the Numerous studies conducted by psychologists Terman found that for the most part these high- population falls within the so-called average range and geneticists over the last 40 or 50 years provide

Arthur R. Jensen is Professor of Educational Psychology and Research Psychologist at the Institute of Human Learning at the Univer- sity of California (Berkeley). Since 1958 his research has included individual differences in human learning, and cultural, develop- mental, and genetic determinants of intelligence in learning ability. He has published over 100 articles and chapters in psychological and educational Journals and books. His re- searches have suggested a strong genetic fac- tor in human intelligence. His article in the Harvard Educational Review (Winter 1969) has caused considerable controversy. 13 THE SATURDAY EVENING POST Summer 1972 an answer to this question. The answer is un- Do I.Q. Tests Measure that there are other important human qualities be- ambiguous and is generally agreed upon by all Intelligence? sides the ability to take scholastic aptitude tests, scientists who have considered all the evidence. but as Wing and Wallach (1971) have shown, This evidence strongly supports the conclusion DAVID c. MCCLELLAND admissions officers may believe they take these that genetic factors are much more important than Psychology has one great practical success to its other qualities into account but in fact their selec- environmental influences in accounting fot indi- credit in the twentieth century-namely the intelli- tion decisions can be almost perfectly predicted by vidual differences in I.Q. How much more impor- gence testing movement. Many tests have been aptitude-test scores alone. The desite to select tant? The evidence indicates that genetic factors devised which predict success in school with re- more "intelligent" people for schooling or for account for at least twice as much of the variation markable regularity. Literally tens of thousands of almost any occupation proves overpowering. It in l.Q.'s as environmental factors. This conclusion validity coefficients have been calculated, demon- quickly reduces other qualifications to insignifi- has one main limitation. Since all of the major strating that those who score higher on aptitude or cance. studies in this field were conducted with samples intelligence tests usually do better in their school of Caucasian European and North American popu- work. Selecting, at random, a finding which is While the intelligence-testing movement in the lations, we cannot confidently generalize their quite typical for the United States, I recently ob- United States has been moving on from one tri- conclusions to other populations, especially those served in a longitudinal study to be reported by umph to the next, some questions have been raised with very dissimilar environments. Costa (1972) that Kuhlman-Anderson I.Q. scores about its theoretical underpinnings, both by obtained in the sixth grade correlated 0.59 with scholars and by policy makers who wonder if its What are the kinds of evidence that lead to the twelfth-grade rank in class. In other words know- growing power over people's lives is justified. One conclusion that genetic differences outweigh ing how a child scores on an intelligence test when difficulty with tests has long been known but little environmental differences in accounting for indi- he is eleven or twelve years old enables you to pre- commented on perhaps hecause its seriousness has vidual differences in I.Q.? Most of this evidence, as dict fairly accurately how well he will be doing in not been fully appreciated. It is very simply that if it is found in the scientific hterature, depends school some six or seven years later. Rank in class academic achievement tests are taken seriously as upon quite technical methods of analysis de- at graduation from secondary school in turn pre- measures of real competence, then the quality of veloped in a specialty known as quantitative genet- dicts whether he can go on to the university and education does not seem to contribute to improv- ics or population genetics. Some of these methods how good a university he will get into. As a con- were devised originally to analyze the roles of ing competence. Back in the 193O's in the United heredity and environment in agriculture and animal breeding. Experiments in Animal Breeding Experiments in which we explicitly try tobreed for some specific trait give us the most certain evidence that variation in the trait has a genetic com- ponent. Psychologists have bred rats for speed of David C. McClelland is Professor of Psychol- learning mazes, which is a good indicator of rat ogy, Harvard University. Appointed to Har- intelligence. By always mating the fast-learning vard in 1956, he has also served as chairman of males with t~ast-learning females, and mating slow- the Fulbright Advisory Panel on Psychology learning males with slow-learning females, it is and as director of research projects for the possible, within 6 to 10 generations, to produce Ford Foundation, the Carnegie Foundation, the State Department, the National Institute two quite distinct strains ot" rats in respect to maze- of Mental Health and the Peace Corps. Pro- learning ability. The slowest-learning rat of the fessor McClelland is author of many books, "bright" strain will learn mazes faster than the including Personality; The Achieving Society; fastest rat of the "dull" strain. The two strains will The Roots of Consciousness; Motivating Economic differ markedly in the number of tries they need to Achievement, and Alcohol and Human Motiva- learn how to run through a maze efficiently, avoid- tion. ing the blind alleys. These experiments definitely prove that not only physical characteristics but some behavioral traits as well are largely inherited through the parental genes. Thus we should not be surprised to find in humans that differences in some behavioral characteristics, including inteUi- gence, are a product of genetic inheritance. Identical Twins Reared Apart sequence, knowing a person's intelligence-test States, a number of private schools tried to im- score or schoiastic-aptitude-test score has become prove the quality of their education as part of what One of the most important lines of evidence for a matter of great importance in the United States, was then known as the "progressive education the inheritance of intelligence in humans comes not only to admissions officers who use it to pick movement." Standardized scholastic achievement from studies of identical twins who were separated people for college but also to businesses and civil tests were used to evaluate the effects of this sup- shortly after birth and reared in different homes. service commissions who use it to decide who is posedly improved education as compared with Identical twins originate from a single fertilized "bright enough" to be a policeman, a social worker more traditional teaching. ovum which splits in the course of early develop- or a fireman. By and large no effects of the supposedly high- ment to form two individuals. Each member of the Testing has therefore become big business. The er-quality education could be discovered in the pair of twins therefore has exactly the same com- Educational Testing Service which gives the test scores. The educators felt they were doing a plement of genes. Consequently, any difference Scholastic Aptitude Test used by most of the bet- better job but the test scores did not indicate that between the twins must be due entirely to non- ter-known colleges and universities in the United they were. The same finding has turned up again genetic or environmental differences. States employs around two thousand people and and again since that time. Certain colleges in the Twins separated shortly after birth are often has a large plant spread over hundreds of acres in United States are widely acknowledged to be bet- reared in families that differ markedly in social Princeton, New Jersey. Thousands of young peo- ter than other colleges—in the sense that they have class, and the range of environmental differences ple pay to take its tests annually to see if they are better faculties, more books in the library, higher observed in their foster homes is fairly typical of qualified to get into the college of their choice. endowments, better laboratory facihties, and so the environmental variations seen in the general The testing technoiogy has been so sold to the forth. Yet repeated studies as summarized by population. American public that only in a few of the more Jacob (1957) have failed to show any test-score Four major studies of identical twins reared "backward" parts of the society is it not used in differences attributable to the better education apart, conducted in England, Denmark, and the the schools or businesses or civil service. And of supposedly obtained in the elite colleges. If the United States, and totaling 122 pairs of twins, are course it is spreading fast to the rest of the world, graduates of those colleges perform better on in remarkably close agreement in showing that which is beginning to discover the utility of tests achievement tests, it is because they scored higher twins reared in different homes are still much more for picking those who will do well in school. on them at entrance to college, not because they received a better education subsequently. Continued on page 149 To be sure, the testers themselves loudly insist THE SATURDAY EVENING POST 149 nonsense and order the machinery he needs to carry out the improve- ments on his property. But he still continued front page 12 insisted on waiting until he heard from the Professor. alike in I.Q. than are fraternal twins tween unrelated children brought up between siblings-that is, about 12 While waiting, we all checked into reared together. Fraternal twins are in different homes but in the same LQ. points. The difference between the GovernorChittenden Motel. The merely siblings who happen to be socioeconomic class. We see that un- a child and the average of both of his rest of our group has been seeing the conceived and born at the same time, related children brought up together parents'I.Q.'sisabout lOpoints. sights of this beautiful city: the and therefore half of them are of the in the same home differ from one A parent with a high LQ. will parks, the University, the Shelburne opposite sex. In I.Q. and other traits another in I.Q. at least 3 or 4 times usually, but by no means always, Museum, the Lake. And I have been they resemble one another no more more than genetically identical twins have children whose l.Q.'s are some- writing this letter, which I wil! mail than do ordinary siblings born at dif- reared in different homes. And the what lower than his own but are still tomorrow morning. ferent times. unrelated children reared together above the average for the general I am sorry I cannot as yet report Identical twins reared apart dif- differ almost as much in I.Q. as un- population. A parent wit ha lowLQ., any definite success. But sometime, fer, on the average, by only 6 to 7 related children simply picked at on the other hand, will usually, but somehow, something may turn up. I.Q. points. But even if we test the random from different homes. not always, have children whose Yours hopefully, very same person on two occasions a The l.Q.'s of adopted children al- l.Q.'s are somewhat higher than his Alexander Bolts week apart, we find that his test so show little or no relationship to own but are still below the average of score will vary, on the average, by 2 the l.Q.'s of their adopting parents, the population. This phenomenon, P.S. The next morning. Tuesday, or 3 I.Q. points. This is the test's discovered by Sir Francis Galton, is but they are almost as closely related called "regression toward the January 25, 1972. Somethinghasin- "measurement error." When we to the l.Q.'s of their natural parents deed turned up. When I entered the mean," and it holds true for height eliminate this error from the twin as we find in the case of children who and other inherited physical traits as Post Office this morning to mail this data, we find that the twins differ are reared by their natural parents. letter, my eagle eye spotted, on a well as for LQ. only 4 or 5 points in I.Q. Identical Children reared in the common l.Q.'s of Husbands and Wives bulletin board, two photographs- twins reared together differ by only environment of an orphanage differ one full face and the other profile— 2 or 3 points, not including measure- from one another in I.Q. to approxi- It is interesting that in our society of none other than Professor Isaac ment error. The largest I.Q. dif- mately the same degree as children husbands and wives are at least as Newton Norton, Ph. D., alias this ference ever found in a pair of identi- picked at random from the total much alike in LQ. as brothers and and that. He was wanted for grand cal twins reared apart is 24 points. population. The l.Q.'s of orphanage sisters. If men and women picked larceny, fraud, and other crimes. I More than 17 percent of siblings their mates strictly at random, as by consulted the local police. They said children who have never known their reared together differ by more than own parents show almost the same a lottery, spouses would differ by an they were certainly after the man. average of 18LQ. points. But in fact And they surmised that the mys- men and women choose one another terious remark, "The fuzz is starting partly for intelligence, and so to buzz," was a warning that the spouses differ by only 10 or 11 cops were after him. 1 took the news points in LQ. to Monkeyface. We both decided the wm The Effect of Inbreeding on I.Q. Professor was on the lam and would not return. Monkeyface then signed Every person harbors a number of a magnificent order for Earthworm mutant, recessive genes. Most of equipment -which is enclosed. these are defective genes. They are passed on from parent to child, but All this makes me feel so good they usually will not produce any that I am repeating the statement I harmful effects to the child unless made in an earlier letter: I am not the other parent also contributes charging anything for my services exactly the same defective gene. The this time. I am also turning down an reason this usually does not occur is offer from Monkeyface, who inci- that each parent's normal genes are dentally is making a generous con- dominant over the other parent's tribution to Miss Gloriana Smith and defective, recessive genes. When the other New York ladies. They are mating occurs between a man and a now very good friendswith Monkey- woman who are blood relations, face, and they are working on anew however, the chances are much slogan for their organization—some- U>^'^ greater that they will both possess thing like "Convert polluters of the "/ guess this just wasn't our day." many of the same defective genes. environment by kindness, not mere- When these defective genes are ly by kicking them in the pants." 24 I.Q. points. The same is true of degree of correlation with their paired together in the related cou- fraternal twins. But siblings (and parents' level of ability as we find in ple's children, they subtract unfavor- This wraps everything up, except fraternal twins) have only half of the case of children reared by their for one nagging doubt: IsthisSuper- ably from the traits that are con- their genes in common, and they dif- own parents. trolled by these genes under normal mohole idea really as crazy as it fer on the average by 12 I.Q. points Resemblance Between Parents sounds? conditions. This depression due to (excluding measurement error), even and Children inbreeding is known to occur in in- Yours, when reared together. Now and then we notice that very herited physical traits, such as stat- A.B. n The studies of identical twins bright parents can have an intellec- ure, and the same thing has been show clearly that individuals who are tually mediocre child, or that rather found for LQ. It is well established, A tree that never had to fight genetically identical are almost as dull parents can have an exception- for example, that cousin marriages For sun and sky and air and light much alike in mental ability as they ally bright child. These observations produce children who, on the aver- But stood out in the open plain are alike in physical traits, and this is are often pointed to mistakenly as age, have l.Q.'s several points lower And always had its share of rain true even when they have grown up evidence that intelligence is not in- than the l.Q.'s of children whose Never became a forest king. in different environments. herited. But the fact is that genetic parents are unrelated but are But lived and died a scrubby thing. Unrelated Children Reared Together theory predicts precisely that we matched with the married cousins on The opposite situation to identi- should find such discrepancies be- LQ., age, educational level, and The man who never had to fight cal twins reared apart is that of tween parents and their offspring. socioeconomic status. More extreme Who never had to win his share genetically unrelated children For example, parent-offspring dif- are the cases of children who have Of sun and sky and light and air adopted at birth by foster parents ferences in height are of about the resulted from incestuous relation- Never became a manly man. and reared together. Such children same relative magnitude as their dif- ships, such as father-daughter and But lived and died as he began. differ from one another, on the ferences in I.Q. Children resemble brother-sister matings. These chil- Good timber does not grow in average, by 1 5 to 16 I.Q. points (ex- their parents physically and in dren show a much higher incidence ease cluding measurement error). Com- mental ability to about the same de- of severe mental retardation than The stronger the wind, the pare this with the 17 to 18 I.Q. gree that they resemble their own children born to the same parents tougher the trees. points difference between unrelated siblings. The average LQ. difference when they have mated with un- J. Willard Marriott children reared in different homes, between a parent and his (or her) related persons. These interesting or the 15 to 16 points difference be- child is the same as the difference 150 THE SMTVRDAY EVENING POST Summer 1972

findings are entirely predictable evitably be due even more to genetic evant evidence contradict the be- lower class and the middle class, the from basic principles of genetics that factors. lief. The reactions have often been majority and the minority, the urban apply to all living beings. Moreover, * * * extreme. In a recent Newsletter of and the suburban, and so on. Educa- it is virtually impossible to explain the American Anthropological Asso- tional differences, not absolute level such facts without concluding that Scholastic Achievement and ciation, for example, it was pro- of performance, are the main cause LQ. differences are very strongly in- Intelligence Statement of posed, apparently in all seriousness, of concern. Whether we like to admit fiuenced by genetic mechanisms. Arthur R. Jensen to the that members of the AAA should it or not, the problem of achieve- The Relative Effects of Heredity U.S. Senate Committee burn—literally burn-all copies of ment differences today is where the and Environment on Education the Harvard Educational Review action is, where the billions of dol- How can we summarize briefly Introduction containing my article! 1 am therefore lars of educational funds are being what is now known about the rela- grateful for this opportunity to poured in, where the heat is on, and Mr. Chairman and members of where the schools are being torn tive importance of heredity and en- the Committee, my name is Arthur make clear my position on these im- vironment in causing individual dif- portant matters to the Committee, apart. We are trying to understand R. Jensen. I am Professor of Educa- more about the causes of these differences in LQ.? In the terminology tional Psychology at the University and also to see that a number of dis- of genetics a summary answer con- ferences. Massive surveys and statis- of California at Berkeley, where I tinguished scientists are concerned tical analyses such as James Cole- sists of saying that the "heritability" have been a member of the faculty with some of the issues I have raised of LQ. is close to 0.80. This means man's well-known report on Equal- for the past 14 years. and are here today to express their ity of Educational Opportunity that 80 percent of the "variance" in First, I want to thank this Com- views. Though I do not expect all l.Q.'s in the general population is at- (1966) have shown that only a small mittee for inviting me to summarize their opinions to coincide com- fraction (about one-tenth to one- tributable to genetic differences and my position on the topics mentioned pletely with mine—indeed, they 20 percent is attributable to non- fifth) of the total variation in scho- in your invitation: "heredity, en- were selected expressly to insure lastic achievement is attributable to genetic or environmental differ- vironment, intelligence, and scholas- that a variety of views might be ex- ences. factors in the schools themselves. In tic achievement." My position on pressed before this Committee—I am other words, differences among "Variance" is essentially a quanti- some aspects of these questions, as especially gratified to see that there schools and school systems nation- tative index of the total amount of you know, is a controversial and un- are prominent scientists who, like wide are not sufficiently large to differences that exist among all popular one, but it is a position myself, are trying to come to grips account for more than a small frac- members of some population. So in- which I have come to through my with these difficult questions now tion of the total variation in scholas- stead of talking about variance, we intensive studies over the past under discussion. tic achievement at any grade level. can more easily describe our conclusions in terms of average differ- The single most powerful pre- ences. dictor of children's scholastic perfor- If we should determine the differ- mance is inteUigence as measured by ences in LQ. between every person in any one of a variety of standard in- the population and every other per- telligence tests: group or individual son, the average of all these differ- tests, verbal or nonverbal. No other ences would turn out to be 18 LQ. variable has yet been found which points. These differences are due makes as large an independent con- both to genetic and to environ- tribution to variance in scholastic mental factors. Now we can ask achievement as does intelligence. I theoretically: What would be the have found in my own research that average LQ. difference among all a composite of several different persons in the population if every- measures of intelligence will predict one had grown up in identical en- nearly all the true variance in scho- vironments from the moment of lastic achievement scores, and the conception, while genetic differ- predictive validity of the intelligence ences remained as they are? Under tests becomes better with advancing this hypothetical condition of com- grade level. Furthermore, the valid- pletely equal environments for ity of intelligence tests for predicting everyone, the average LQ. difference scholastic achievement is not signif- would be 16 points. Thus, there icantly different for white and black would be a reduction of 2 points in "Hi. My name is Percy . . . P as in prison, E aa in evasion, children. In this respect, intelli- the average difference that now R as in receipt, C as in catch, Y as in you . . ." gence tests are quite color blind. exists. Let us now ask the reverse: That is to say, a white child and a What would be the average differ- decade of virtually all the relevant Scholastic Achievement black child with the same I.Q. can be ence if everyone had exactly the evidence in this field and through my and Intelligence expected to perform about equally same genetic endowment, but en- own experimental and statistical in- Scholastic achievement is what well in school. In short, if intelli- vironmental differences remained vestigations. The reporting of these children learn in school-repertoire gence tests can be said to be good for unchanged? Under this hypothetical conclusions in scholarly journals, as of knowledge and skills, including anything, they are good for pre- c o n d i t i on of complete genetic in my well-known article in the the 3 R's. Scholastic achievement dicting scholastic achievement. equality the average LQ. difference Winter 1969 issue of the Harvard can be most reliably measured by among persons would be only 8 Educational Review, has not been means of standardized tests at every Intelligence, in the technical points, or just half the difference without some penalty. At least I stage of schooling from kindergarten sense that psychologists use this that would exist with equal environ- have heard of no one taking the con- to college. When entire school popu- term, is not the same thing as scho- ments. trary position who as a result has had lations are tested on scholastic lastic achievement. Schools do not to endure personal threats, pro- achievement, there is revealed a wide teach intelhgence per se. Intelligence So the conclusion we come to— longed harassment, invasion of his range of individual and group dif- is mental brightness; it is a capacity which is certainly valid at least in the college classes by disruptive demon- ferences at any given grade level. In for conceptualization, abstract white European and North Ameri- strations, or has had his university one fifth-grade classroom in San reasoning and problem solving, for can populations in which the re- administration take such pre- Francisco, for example, achievement processing information in the form search was conducted—is this: In cautions as putting two plainclothes levels ranged from first to eleventh of words and symbols, for integrat- accounting for the causes of the dif- police bodyguards on him-in lec- grade. What most educators, govern- ing and understanding what is ferences among persons in LQ., the tures, on the campus, in going to and ment officials, and writers in the learned, and for making broad trans- genes outweigh the effects of en- from classes and to the parking lot. popular press who talk about the fer from past learning to the solution vironment by 2 to 1. As environ- Much of this emotional reaction to present problems of education are in of novel problems. As Harvard mental conditions are improved and my Harvard Educational Review fact referring to is not primarily dis- psychologist Professor Lawrence made more alike for all persons in article, I believe, is a result of the fact satisfaction with so me a &.SO/U re level Kohlberg recently noted, scholastic the society, the average intelligence that a generation of social scientists of achievement, but rather with the achievement merely rides on the level of the population will be some- and educators has been assiduously large group differences in educa- back of intelligence: "... bright what increased, and the LQ. dif- indoctrinated to believe that genetic tional attainments that show up so kids learn the stuff they're taught in ferences among persons will be factors are of little or no importance conspicuously in our educational school faster, but learning the stuff slightly reduced. But of course the in human behavior and human dif- system-the achievement gaps be- they're taught in school doesn't differences that remain will in- ferences. My summaries of the rel- tween the affluent and the poor, the make them brighter" {Education THE SATURDAY EVENING POST iSi

Summary, August 6, 1971). total variance which is genetically ally of the order of .70 to .80.) 1 be- individual differences in intelligence Intelligence can be quite reliably determined, is a population statistic lieve it is safe to say that in European as assessed by standard tests. measured by appropriate tests, and subject to samphng error and other and North American Caucasian these measurements, often called sources of variation, it has no univer- populations at the present time, Educational Implications l.Q.'s, show substantial correlations sal or constant value for all times, all genetic or hereditary factors are At present, neither I nor anyone with a number of educationally, oc- tests, and all populations. But em- roughly twice as important as en- else, I'm afraid, has any more than cupationally, and socially important pirically determined values are usu- vironmental variation as a cause of rather general notions concerning criteria. The correlations are not appreciably different for children of the rich than for children of the poor, for whites or for blacks. Although intelligence, as psychologists use this term, is the single most powerful, though by no Prosperity '^ yours means perfect, predictor of academic performance, it is surely not the whole of mental ability and human competence. To equate in- for 50^ a day! telligence with all virtue is a ridiculous mistake. But in THE LAND BUY OF A LIFETIME... discussing achievement differences in schools with SAN LUIS VALLEY RANCHES their present curricula and IN BOOMING COLORADO! their present instructional methods, intelligence differences, we know, are of PER ACRE central importance. 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The make better use of these opportunity for profits like this in Denver are gone ... but YOU CAN BUY WHERE THE GIANTS INVEST! other abilities for scholastic a new area of Colorado is opening for public sale for the You can feel a lot better about buying land where you know learning. first time ... large corporations are investing. In the San Luis Valley, Forbes, Inc., publishers of the world's most respected SAN LUIS VALLEY RANCHES financial magazine, recently bought a giant 168,000 acre Both intelligence and The future here is unlimited. The San Luis Valley Ranches ranch nearby San Luis Valley Ranches. Malcolm Forbes, scholastic achievement are located in the heart of the beautiful San Luis Valley, their president, publicly stated that he will turn the ranch grow or increase in a quite surrounded by ranges of the Rocky Mountains. This is beau- into the largest and best known game preserve in the coun- regular manner in most tiful land, level to rolling. The air is clean; the climate try, leaving the natural beauty untouched children, and their indi- healthy. All Ranches are accessible by graded roads. This is a perfect place for raising children, retirement or as a THE PRICE IS STILL LOW —NO DOWN PAYMENT! vidual mental growth vacation paradise. *Just $395.00 per acre in 5 acre parcels. Your total monthly curves become increasingly payment is $15.00, LESS THAN 50c A DAY. There is no stable over the years from RECREATION "^ down payment, no interest, no salesman commissions, no infancy to maturity. carrying charges of any kind. Every cent you pay is applied Every outdoor recreation is here. Hunting for duck, elk, to the purchase price of your land. The Heritability of deer and bear. Camping and exploring in the Rio Grande Intelligence National Forest. You'll find great fishing, boating and water WATCH YOUR DOLLARS GROW... A number of genetic skiing within 3 miles of your property. Wolf Creek Pass, Remember, this is acreage, not just a little plot of ground. studies carried out in Eu- only 60 miles away, offers wonderful skiing and winter Your 5 acre ranch will be equal in size to 20 city lots. rope and the United States sports. Yes, the San Luis Valley is truly a scenic and recre- We all know about the fortunes made by original investors over the past forty years ation wonderland. in Denver. So ... provide evidence which ALL THIS AND MODERN CONVENIENCES TOO! ACT NOW —RANCHES ARE GOING FAST shows quite conclusively The cities of Alamosa and Blanca are friendly neighbors, i As you might imagine, property at this price and these that, in the populations with stores, supermarkets, schools, churches and a hospi- 4 terms is going fast. Return the Reservation Form and a 5 studied, a very substantial tal. Blanca is less than 3 miles and Alamosa 14 miles from acre parcel will be reserved in your name. No obligation, proportion of the variabil- San Luis Valley Ranches. Alamosa is the home of Adams ACT NOW! ity among persons in intelligence is attributable to GUARANTEED SEP-fi-72 genetic, i.e., inherited, fac- SAN LUIS VALLEY RANCHES / BOX 836 / ALAMOSA, COLORADO 81101 tors. The vast majority of INVESTMENT PLAN YES, RESERVE a 5 acre Ranch for me. I understand the price is $395 per studies have found that the acre (total price $1,975) and my total monthly payment for the 5 acres will BUYER MAY AT ANY TIME, WITHIN be $15 ... no down payment. . . no interest nor carry charges. Please rush proportion of population ONE YEAR FROM DATE OF THE CON- complete details, FEDERAL LAND REGISTRATION REPORT, purchase contract variance attributable to TRACT, COMPLETE A COMPANY and map showing the exact location of my property, n Enclosed is my $1 genetic differences is some- GUIDED TOUR OF THE SAN LUIS reservation deposit which will be credited to my account or fully refunded at thing between the extreme VALLEY RANCHES AREA, AND, IF NOT my request within 30 days. Reservations subject to prior sale. SATISFIED. REOUEST tN WRITING A limits of about .60 to .90, a REFUND OF ALL MONIES PAID ON THIS OFFER IS SUBJECT TO ALL LOCAL, STATE AND FEDERAL REGULATIONS. figure known as the heri- THE CONTRACT. THIS REQUEST Name. tability (in the broad MUST BE EXECUTED IMMEDIATELY sense). (Since heritability, UPON COMPLETION Of SAID TOUR. i.e., the proportion of the -State & Zip_ 153 THE SATURDAY EVENING POST Summer 1972 the educational implications of the cational opportunity should neces- eliminate human differences. Rather them, if not in the usual academic wide range of apparent differences in sarily lead to equality of perfor- than making over a large segment of sense, then in ways that can better educability in our population. mance, I believe, is proving to be a the school population so they will their chances for socially useful and There is fundamentally, in my false hope. It is the responsibility of not be doomed to failure in a largely self-fulfilling roles as adults. E opinion, no difference, psychologi- scientific research in genetics, antiquated, elitist-oriented, educa- California Institute of Technology En- cally and genetically, between indi- psychology, and education to deter- tional system which originally evolv- gineering and Science magazine, Pasadena, vidual differences and group differ- mine the basis for realistic solutions ed to serve only a relatively small seg- California, April, 1970. ences. Individual differences often to the problems of universal public ment of society, the educational simply get tabulated so as to show up education. Though it may be pre- system will have to be revamped in as group differences between mature to prescribe at present, I order to benefit everyone who is re- schools in different neighborhoods, venture the prediction that future quired by the society to attend between different racial groups, be- solutions will take the form not so school. It seems incredible that a tween cities and regions. They then much of attempting to minimize dif- system can still survive which virtu- contxnuvd from page 14 become a political and ideological, ferences in scholastic aptitudes and ally guarantees frustration and failure for a large proportion of the not just a psychological, matter. To motivation, but of creating a greater too far from familiar territory. Yet if children it should intend to serve. reduce the social tensions that arise diversity of curricula, instructional he says he would go home he is therefrom, we see proposals to abol- methods, and educational goals and But we should not fail to recog- judged by the testers to be less intel- ish aptitude and achievement test- values that will make it possible for nize that to propose radical diversity ligent. It is also easy to see from ing, grading, grade placement, spe- children ranging over a wider spec- in accord with individual differences these examples why there is a cor- cial classes for the educationally re- trum of abilities and proclivities in abilities and interests, as con- relation between test performance tarded and the academically gifted, genuinely to benefit from their years trasted with uniformity of educa- and later performance in school be- neighborhood schools, the class- in school. The current Zeitgeist of tional treatment, puts society because the teacher, as a representative room as the instructional unit, the environmentalist equalitarianism has tween Scylla and Charybdis in terms of standard middle-class culture, will academic curriculum, and even our all but completely stifled our think- of insuring for all individuals equal- expect the same language and types whole system of education. There ing along these lines. And I believe ity of opportunity for the diversity of behavior as the person who made may be merit in some of these pro- the magnitude and urgency of the of educational paths. The surest way up the so-called intelligence test. The posals. But I think they are too often problem are such as to call for quite to maximize the benefits of school- teacher will either not understand aimed at covering up problems radical thinking if the educational ing to all individuals and at the same the dialect that is used in class or will rather than coming to grips with give the child a lower mark for using them. "bad" language and the ghetto child Greater Attention to Learning will before long go through life stig- Readiness. The concept of develop- matized as being less intelligent and a mental readiness for various kinds of poor student. school learning has been too ne- Looking at the problem this way glected in recent educational trends, forced psychologists to consider which have been dominated by the seriously another possible explana- unproved notion that the earlier tion for many of the existing correla- something can be taught to a child, tions between intelligence test the better. Forced early learning, scores, doing well in school, and prior to some satisfactory level of holding down higher-status jobs later readiness (which will differ marked- in life. Those who control not only ly from one child to another), could economic and social opportunities cause learning blocks which later on but also what language and values are practically defy remediation. The the standards by which others will be more or less uniform lockstep se- judged, may in fact be able to use quencing of educational experiences test scores to maintain their power. may have to be drastically modified All one needs to assume is that more for the benefit of many children, but powerful families are in a much bet- the recent massive insistence on ter position to help their children get "earliness" and equality of educa- higher-status jobs: they know the tional treatment of all children has . You, Peabody, are one crummy Puritan! right people; they can send their chil- militated against large-scale research dren to the right schools; they can use their influence to get them jobs on the implications of readiness for system is truly to serve the whole of time to make the most of a society's children with below-average edu- directly. So it turns out that people society. We have invested so much human resources is to insure equality in higher-status jobs score higher on cability within the traditional school for so long in trying to equalize of educational opportunity for all its so-called intelligence tests. system. scholastic performance that we have members. Monolithic educational Greater Diversity of Curricula given little or no thought to finding goals and uniformity of approaches But where is the direct evidence and Goals. Public schools, which aim ways of diversifying schools to make guarantee unnecessary frustration that the higher score on the test in to serve the entire population, must them rewarding to everyone while and defeat for many. On the other fact indicated that the person was move beyond narrow conceptions of not attempting to equalize every- hand, educational pluralism runs the better able to do the higher-status scholastic achievement to find a one's performance in a common cur- risk that social, economic, ethnic job? As every psychologist knows, greater diversity of ways for children riculum. Recommendations have background or geographic origin, correlation does not mean causation. over the entire range of abihties to almost always taken the form of ask- rather than each child's own charac- It doesn't follow that because pro- benefit from their schooling-to ing what next we might try to make teristics, might determine the edu- fessionals score higher than laborers benefit especially in ways that will children who in the present school cational paths available to him. The on certain tests that it is the ability be to their advantage when they are system do not flourish academically individual characteristics appropri- to perform those particular tests out of school. The academic goals of become more like those who do. The ate for any one of a variety of educa- which enabled them to be profes- schooling are so ingrained in our emphasis has been more on changing tional paths and goals are to be sionals rather than laborers. The thinking and our values that it will children than on revamping the found everywhere, in every social reason why people have assumed probably call for radical efforts to system. A philosophy of equaliza- stratum, ethnic group, and neighbor- that causation was involved is that modify public education in ways tion, however laudable its ideals, hood. Academic aptitudes and spe- the test scores were supposed to indi- such that it will maximally benefit cannot work if it is based on false cial talents should be cultivated cate how intelligent the person was, large numbers of children with very premises, and no amount of propa- wherever they are found, and a wise and it seems reasonable to assume limited aptitude for academic ganda can make it appear to work. society will take all possible mea- that being a professional requires achievement. I believe that a well- Its failures will be forced upon every- sures to insure this to the greatest more of something called intelli- intentioned but misconceived social one. Educational pluralism of some possible extent. At the same time, gence than being a laborer does. egalitarian ideology has prevented sort, encompassing a variety of very those who are poor in the traditional However it is by no means as self- public education in the United different educational curricula and academic aptitudes cannot be left by evident as it once was that these test States from facing up to this chal- goals, I think, will be the inevitable the wayside. Suitable means and scores measure the kind of intelli- lenge. outcome of the growing realization goals must be found for making their gence implied by the logic of this that the schools are not going to years of schooling rewarding to The belief that equality of edu- Continued on page 154