this is a very old article. For a slightly different slant on this issue try, richard lynn "IQ and the Wealth of Nations" he looks at national iq scores gathered from a variety of sources and correlates the scores with national wealth.
----- Original Message ----- From: "alypius skinner" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, July 02, 2003 3:34 AM Subject: IQ, birthrates, and economic performance > "...in not too many generations differential fertility could swamp the > effects of anything else we may do about our economic standing in the > world." > > > http://www.slavin.uk.net/texts/birth.html > > > > IQ and falling birthrates > R.J. Herrnstein > The Atlantic, May 1989 v263 n5 p72(7) > > Bright, well-educated American women of all races are having fewer children, > a phenomenon the author believes may affect national productivity and the > gene pool > > > -------------------------------------------------------------------------- -- > ---- > > A GREAT MANY PEOPLE ARE ANXIOUS ABOUT HAVING children. I hear about this > concern frequently from young men and women passing through Harvard-more > than ever before in my three and a half decades here. And I hear about it in > conversations with my peers, frustrated by the slow accumulation of > grandchildren. This concern is at least mildly ironic, coming, as it does, > two decades after alarms about a "population explosion." > > Though populations in South America and Africa and the Indian subcontinent > continue to grow at an alarming rate, the U.S. media direct their attention > increasingly to labor shortages in industrial societies and to shrinking > school populations in affluent American suburbs. Thinking people have heard, > and are talking, about the "birth dearth," as Ben Wattenberg named it in the > title of a recent book. Day-care and parental benefits, which will > presumably increase the birth rate, earn approving mention in the platforms > of both political parties and in glossy annual reports of large companies. > > The concern about fertility also bubbles to the surface in artistic > renderings of contemporary and future life-in light movies like Baby Boom > and Three Men and a Baby, for example, about young women or men trying to > reconcile careers and parenthood, and in serious novels, like Margaret > Atwood's Handmaid's Tale, with its fantasy of a not-too-distant future in > which the dwindling number of fertile women are made slaves to procreation. > > Low fertility, of course, is hardly a new worry. Some of its history, > especially that in Europe since the middle of the nineteenth century, is > well and compactly told by Michael Teitelbaum and Jay Winter in their book > The Fear of Population Decline. Some French writers attributed the defeat of > their nation in the Franco-Prussian War, in 1871, to the slow French rate of > reproduction, as compared with that of fecund Germany. Fertility became a > central issue in early-twentieth-century French politics. Besides being > blamed for France's inability to field an army large enough to defeat the > Germans and also have a functioning economy at home, low fertility was seen > by various contemporary French commentators as the cause or the effect of > "national degeneracy," a disease of the French spirit. > > Fiction echoed reality, as it does everywhere. In Emile Zola's novel > Fecondite, written at the turn of the century, happiness and personal > triumph came to a working-class couple with fifteen children and scores of > grandchildren, rather than to various unappealing bourgeois, with their > selfishly hedonistic but ultimately miserable lives, their Malthusian > rhetoric bemoaning fecundity, and, above all, their small families. Zola was > one of the founding members of the National Alliance for the Growth of the > French Population. > > In Great Britain, too, arguments about reproduction were part of the > political landscape before and after the turn of the century. As in France, > a disastrous and costly war heightened public alarm. But the British had > been outfought in southern Africa, rather than outnumbered, by the Boers, > even though the British eventually won the war. Considerations of the losses > of the Boer War emphasized not so much the question of how many British > soldiers but of how good they were. If the French worry about fertility was > characterized as mainly quantitative, the British worry was mainly > qualitative. > > The worries went beyond the quantity and quality of armies. Teitelbaum and > Winter describe a British preoccupation with the general "physical deteriora > tion" of the population; with what was called the residuum, meaning urban > unskilled workers; and with the "proliferation of the unfit" versus the > underreproduction of the fit. Prime Minister Arthur Balfour worried publicly > in 1905 that the very members of the working class who showed the enterprise > and ability to improve their lot were the ones who limited their own > fertility, while those who did not get ahead bred beyond their capacity for > taking good care of their children. "Everything done towards opening up > careers to the lower classes did something towards the degeneration of the > race," he said. > > In our time, Prime Minister Lee Kuan Yew, of Singapore, has said, "Levels of > competence will decline, our economy will falter, our administration will > suffer, and society will decline" because so many educated men are failing > to find educated women to marry and are instead marrying uneducated women or > remaining unmarried. But Lee is an exception, for few modern political > leaders dare to talk in public about the qualitative aspect of low > fertility. We know why this is, and it has less to do with whether or not we > have a fertility problem than with the unacceptability of talking about the > subject. In our century the Nazis made selective fertility an emblem of > National Socialism, with malevolent consequences that need no review here. > Hence even to mention fertility in relation to nation or race has become > taboo. > > Nonetheless, human fertility, particularly in its qualitative aspect, has a > special and direct relation to economic productivity. A full study of > fertility and productivity would, of course, cross many frontiers of > scholarship, but my focus is narrower. My subject is differences among > groups within the population: how these differences affect fertility and how > that, in the long run, may affect the society's economic well-being. Partly > because of our ghastly memories of the Nazis, many social theorists and > scientists have for some time been reluctant to take such differences into > account. Society, these social scientists say, must be studied at the level > of broad social forces, not at the level of small subpopulations. But > however useful and illuminating the abstractions of social theory are, the > actual life of a society must consist of myriad individual human actions. In > the present instance the social consequences of reproduction are illuminated > by the study of individual differences, and the light it sheds spreads > further than many realize. > > Population > > IN PREINDUSTRIAL SOCIETIES PEOPLE TYPICALLY DIE and have babies at high > rates, the difference between the two rates determining the direction and > size of population growth (if we set aside complications like migration and > age at reproduction). With the advent of industrialization, mortality rates > fall. Since birth rates remain high, the first consequence of > industrialization is a rise in population. This is what alarmed Thomas > Malthus, who wrote at the end of the eighteenth century to warn of the > tendency of populations to expand to the point of marginal subsistence. > > Malthus could not have known that in the next stage of this process of > demographic transition, as it is known among demographers, the birth rate > falls, largely or totally compensating for the fall in mortality rates. The > average number of live births per American woman, for example, fell from > about eight in the 1700s to about two in the 1970s. The timing and size of > the two components of the demographic transition-the fall in death rates and > the fall in birth rates-may vary from nation to nation, but the transition > itself is as close to a demographic universal as social science has > discovered. > > This purely quantitative aspect of the transition is quite well known, > unlike the qualitative aspect, which may in the long run be no less > significant socially. Robert Retherford, of the East-West Population > Institute, in Honolulu, has examined dozens of empirical studies, from many > countries, of the demographic transition in relation to social status. The > evidence shows that prior to the transition women of high status had higher > fertility than those of low status. Among the possible reasons for this: > high-status women usually enjoyed better health, they married earlier, > because their spouses could afford to start families earlier in life, and > they endured fewer and shorter separations from their spouses than > low-status women did. > > After the transition the overall birth rate is lower, but now women of high > status usually have lower fertility than those of low status. Health and > marital separation cease to be major factors in fertility, and because of > the educational opportunities open to women of high status or high > intelligence, their age at marriage rises above that for women who, for > whatever reason, lack those opportunities. More-subtle changes, involving > the social relation between men and women, may further depress fertility, > especially at the upper end of the social and intellectual range. > > With only rare exceptions, according to the evidence that Retherford has > assembled, the fall in fertility during the transition is thus not just a > fall but also a redistribution. At first glance the demographic transition > seems biologically perverse. Why do people limit their fertility just when > improved conditions of life-as reflected in the reduced mortality rate-might > allow them to raise more children successfully? And why should more > limitation of fertility take place at high social-status levels than at low? > Theorists have several hypotheses. > > Economic theorists have noted a simple economic fact about > industrialization, one that may influence people's decisions about family > size. Economic resources flow from children to parents before > industrialization, and vice versa afterward. Another pair of hands on the > farm is transformed, after the demographic transition, into another mouth to > feed or another tuition to pay. Industrialization and modernization may tip > the economic balance toward small families, and do so at higher > social-status levels more than at lower, if people calculate consequences at > all rationally, as economists usually assume they do. > > Theorists with a more biological orientation have suggested that after > industrialization people may focus more on the quality of offspring than on > the quantity. A few well-nurtured children may have been, at some point in > our evolutionary history, a better long-term strategy for the survival of > parental genes than many children at the brink of extinction. This means > that those who have fewer children may, theoretically, have more > grandchildren who reach reproductive age. Biologists theorize that from the > evolutionary pressures of such an era, if it existed, we may have inherited > behavioral dispositions that favor lower birth rates as conditions improve > on the average-as they do in the transition to an industrialized society for > those who succeed in that society. Whether or not the reduced birth rate > after industrialization is justified rationally is beside the point as far > as this theory is concerned, for the inherited traits of an era arise from > the selective processes of an earlier era. > > Another biological approach to the demographic transition looks at the > differing pressures of parenthood on women and men. Females and males > inevitably have different investments in offspring. Mothering is more > depleting than fathering. For example, the number of ova per woman is quite > limited, compared with the virtually unlimited number of sperm per man. A > woman can have little more than one pregnancy a year; a man has no such > limitation on his reproductive rate. Each of a woman's children represents a > greater fraction of her reproductive potential than does each of a man's. > Because she invests more in each child, she is more vulnerable biologically, > and perhaps psychologically, to anything that threatens an offspring. > Because of this special vulnerability, the customary sexual division of > labor-whether or not its origins are inherited-places on mothers a > disproportionate share of the burdens of child-rearing. > > One difference between human beings and their close biological relatives is > that human intelligence has made salient the different stakes that women and > men have in parenthood. As human intelligence evolved, women came to > understand more clearly than their simian ancestors the risks, pains, and > obligations of motherhood, and how these contrasted with the consequences of > fatherhood. Women should therefore have come to prefer smaller numbers of > children, and they have. They may want the first child or two as much as or > more than their spouses do, but in the aggregate women in most societies who > express a preference for a particular family size prefer small families, and > in few societies do they prefer large ones. Further, women who express a > preference-suggesting that they feel they have a say in family size-tend to > have fewer children than those who, fatalistically, do not express any > preference at all. > > No species can survive in the long run, however, if its female fertility > falls below what demographers call the replacement rate: the number of > children an average woman must have in order to maintain a constant number > of women from generation to generation. Since our species continues to > flourish, the tendency toward childlessness must, therefore, have been > counteracted by evolution and by culture, during the hundreds of thousands > of years since the dawning of human intelligence. > > One theory defended by a number of contemporary researchers holds that birth > rates drop when a society modernizes if one of the corollary effects is to > free women to any extent from the cultural pressures forcing them toward > motherhood or keeping them subservient to men. If, for example, they become > less dependent on or less threatened by men, and more free to choose a style > of life, they will, if the theory is right, choose fewer children. They can > just say no. > > Inexpensive contraception should hasten the decrease in fertility as women > are liberated, by separating the rewards of sexual activity from the costs > of parenthood. Contemporary women may choose sex and reject motherhood, an > option unavailable to women sexually oppressed and without access to birth > control. The calls for the right to abortion come largely from these > contemporary women. This theory implies a differential fall in fertility > within a society. The number of offspring may decrease most among > more-intelligent women, since they are most aware of the costs of > motherhood, all of which are deferred from the moment of fertilization. Sex > comes first, the pains and costs of pregnancy and motherhood later. Much > research suggests that the less intelligent people are, the less they are > likely, on the average, to be influenced by the delayed consequences of > their behavior. Women from the higher social strata-and more-intelligent > women-are also likely to have fewer children because they are more likely to > find rewarding occupations other than, and competing with, motherhood. > Societies that manage to keep women subjugated while industrializing should, > according to this theory, avoid or reduce the qualitative effect of the > demographic transition. Their women-especially their advantaged women-should > have more children relative to the historical norms of their society than > comparable women in other industrialized societies. > > While all these theories about the failing birth rates of the demographic > transition are probably right to some extent, the exceptions to the general > pattern are well explained by taking sex-role differences into account. The > relevance of women's rights to the demographic transition is exemplified by > the experience of Japan. Daniel Vining, a demographer, has summarized the > evidence showing that educated, upper-class Japanese women did not bear > fewer children than women lower on the social ladder as their country grew > industrially after the Second World War, and they also did not enjoy as much > cultural and economic liberation as did women in modern societies elsewhere. > Japan seems to have passed through the quantitative aspect of the transition > without experiencing much of the qualitative, reducing fertility rates more > or less uniformly all along the social scale. In the Muslim nations as well, > childbearing has not shifted disproportionately to women of lower strata, > and in that culture, too, women have by Western standards remained > oppressed. > > WE MIGHT BE CONCERNED ABOUT THE REDISTRIBUtion of childbearing toward lower > social strata for many reasons, among them the correlation between social > status and socially important traits. Intelligence, as measured by > intelligence tests, is one such trait. Because parents and children tend to > have comparable levels of measurable intelligence, the average intelligence > of the population will decline across generations to the extent that > reproduction shifts toward the lower end of the scale (assuming no other > influence on the average level). This decline does not depend only on the > genetic factor in intelligence, even though most contemporary researchers > say that the genetic factor is large. Differential reproduction shifts a > population toward the characteristics of the more prolific parents for all > traits in which parents and children resemble each other, for whatever > reason. > > Are brighter women, in fact, having fewer children than less bright women in > the United States? Except for the time of the (atypical) Baby Boom, > fertility and tested intelligence have been negatively related in several > national samples of Americans. The best, albeit still tentative, estimates > imply about a one-point drop per generation over the population as a whole, > other things being equal. The decline would be larger in the black > population than in the white, because black women show a steeper fertility > differential in relation to IQ. Using historical estimates of overall > American birth rates, Vining tentatively infers the equivalent of a > four-to-five-point drop in IQ over the five or six generations spanning the > demographic transition in the United States, with only the Baby Boom > generation's IQ not dropping. This may not seem like much, but the drop is > large if we consider the "tails" of the distribution of intelligence and not > just its average. For example, a five-point drop in the average, if the > distribution of scores has the "normal" (that is, the familiar bell-curve) > shape, would result in almost a 60 percent reduction in the fraction of the > population with IQ scores over 130 and a comparable increase in the fraction > with IQ scores below 70. It may be the tails of the distribution, more than > the average, that we should be worrying about. > > The Japanese population has a higher average IQ than the American. In public > discussion this IQ differential is usually attributed to the superiority of > Japanese schools, but the difference is already present in the earliest > years of primary school, and has grown in recent generations. The superior > IQ scores of the Japanese population may be to some extent yet another > consequence of the demographic transition, which, as noted above, has had > less of a differential effect within Japan than it has had here. > > Productivity > > AN IQ POINT OR TWO ON THE AVERAGE SEEMS A SMALL price to pay for the other > consequences of modernization, especially the liberation of women. So why > should we care if the intelligence of our population is shifting downward? > Can we not compensate in our schools for whatever small cost we are paying > in lost intellectual ability? That is certainly a possibility, but most > people who express that hopeful notion underestimate the cost we pay, > economically and perhaps otherwise as well, for lost IQ points. > > As a rule of thumb, more-educated people in a modern society are more > intelligent, as measured by standard tests, and vice versa-chiefly because > societies usually invest educational resources in the people who make the > best use of them, and that usually means the people with the high scores. > Whether or not one approves of it, education and intelligence are thus > correlated-but they are not identical. They can be pulled apart, at least a > bit, as a matter of public policy. During the Cultural Revolution in China a > centuries-old Chinese tradition of educational selection by objective tests > was for a time abandoned. Closer to home, judges and legislatures in this > country have been regulating or banning the use of objective tests for > school placement and university admissions. > > Occupational success in modern societies is linked to education. For decades > study after study has shown that people who do well in school are more > likely also to do well socioeconomically. Therefore, one line of reasoning > goes, the key to productivity and individual achievement is education-rather > than individual traits that predict educational success. > > If that reasoning were sound, we would be in increasingly excellent shape, > compared with the rest of the world. The United States has decisively left > the competition behind in sending its population to school. From 1900 to the > present the proportion of the American population completing high school > rose from 10 percent to over 70 percent. In the 1970s about half of all high > school graduates went to college. In the Soviet Union, in contrast, about 10 > percent of all high school graduates (who are a smaller fraction of the > population to begin with than are graduates in the United States) went on to > the next level of education. Western European countries and Japan also fall > short of the American standard, graduating fewer than 70 percent (in Italy, > the Netherlands, and West Germany the number is fewer than 20 percent) of > their high school students, and admitting far fewer of those graduates to > college. Similarly, American schoolteachers have, on the average, more years > of post-secondary education than teachers anywhere else. > > Sending more people to school has no doubt produced benefits in the quality > of American life, but instead of an educated populace, we find widespread > illiteracy and its mathematical equivalent, innumeracy. Many Americans are > going to school more but, apparently, learning less. Schools are being > criticized for their lack of rigor, for failing to instill a love of > learning; society as a whole is criticized for underpaying and > underappreciating teachers. These criticisms may in time lead to > improvement. For the present, however, the fact is that the expansion of > schooling has not done the job we expected it to do, and its disappointments > are evident not just in the classroom. While America has been sending more > people to school, it has also been losing ground in the growth of worker > productivity, compared with nations having less-schooled populations, such > as Japan and West Germany. We now know, to our regret, that something more > fundamental than schooling per se explains the historical role of education > as a ladder to economic success. > > Thanks to a remarkable series of studies by applied psychologists, > especially John Hunter, Frank Schmidt, and their associates, we know quite a > lot about the predictors of individual occupational success in the United > States. Overturning the conventional wisdom of several generations of > experts, their analyses prove that variations in intelligence, as measured > by IQ and IQ-like tests (such as the U.S. Employment Service's General > Abilities Test Battery), predict job productivity to an extraordinary > degree. > > Because job performance is correlated with intelligence, we now know not > only that the productivity of the American work force as a whole, and within > particular occupations in given locations, can be improved by the use of > intelligence tests for job placement, but also how much improvement is > possible. For example, one analysis estimated that Philadelphia would lose > $170 million in productivity over a ten-year period by not using an > intelligence test when hiring recruits for the police department. Losses > that are larger per person hired would be incurred by failing to test > applicants for jobs demanding greater cognitive complexity, such as computer > programming. For the American work force as a whole, after taking into > account the number of people at all levels of intelligence, the productivity > differential between a labor force selected by intelligence tests and one > selected at random from applicant pools was estimated to be worth a minimum > of $80 billion in 1980-about the size of the total annual corporate profit > for the Fortune 500 in that year. > > When these new analytic methods are applied to thousands of separate studies > of worker performance in relation to intelligence, certain broad > generalizations follow. Intelligence tests predict performance (as measured > by on-the-job trainability, objective measures of job proficiency, or > supervisor ratings) in hundreds of common occupations. Performance in a job > requiring greater cognitive complexity, such as the job of manager, is more > strongly associated with intelligence than performance in one requiring > less, such as that of sales clerk. But even for a job at the lowest level of > cognitive complexity, such as off-loading conveyor belts, intelligence has > predictive power. > > The predictive validity of intelligence-test scores, expressed as a > correlation coefficient between the score and some measure of job > performance, seems to vary from about 0.2 to about 0.6 for individual > occupations, and to average about 0.5 for the work force as a whole. If this > finding holds up, it is an astonishing result. It says that on the average > about 25 percent of the variation in worker productivity can be accounted > for by the scores on intelligence tests that can be administered in an hour > or so. > > Performance in occupations demanding little cognitive complexity is usually > best predicted by scores on tests of psychomotor skills (eye-hand > coordination, simple reaction time, and so forth), rather than on tests of > intellectual ability. Therefore the use, for hiring and promotion, of some > combination of intelligence and psychomotor scores, suitably weighted for > particular occupations, would predict job productivity even better than the > use of either or, obviously, the use of neither, which seems to be a fond > hope of advocates of various causes. > > One study compared intelligence-test scores with ten other plausible > predictors of productivity (job tryout, biographical inventory, reference > check, experience, interview, training and experience ratings, academic > achievement, education, interest, and age) of entry-level employees in a > variety of occupations. All the variables except age had some predictive > validity, but intelligence scores, with a validity coefficient of 0.53, had > the most. Near the bottom, with coefficients of 0.11 and 0.10, were academic > achievement and education, respectively. For employees already on a job, > intelligence scores predicted performance after promotion as well as, or > better than, measures based on past performance. > > Educational level may be a better predictor than intelligence of > occupational attainment in the United States, as many studies have shown, > but for occupational performance, intelligence is the better predictor by > far. Employers may use educational credentials to hire or promote their > employees because they do not understand the power of, do not have > available, or are simply reluctant to use measures of intelligence. But the > failure to use intelligence measures seems costly in terms of productivity. > The evidence also shows that the distribution of intelligence matters in its > own right, and not just in relation to the effect of intelligence on success > in school. > > WHAT ARE THE IMPLICATIONS? FIRST, AT THIS POINT in our history merely > sending more people to school for more years seems to offer little benefit > to economic performance, although doing so may be worthwhile for other > reasons. At one time schooling was largely reserved for socioeconomically > privileged people. Opening the schools to the rest of the population > harvested a vast benefit, intellectually and economically, but we seem to > have passed the point at which a large economic gain can be made by merely > increasing access to schooling. > > The data suggest, however, that schools could be improved so as to develop > the very intellectual skills that are so predictive of productivity, and > perhaps to further other social purposes. Even the most confirmed believer > in the genetic factor in intelligence knows that the environment contributes > significantly. Most such believers would probably also agree that schools > can play a major role in developing intelligence. For schools to do so would > take new knowledge about cognitive development and a redirection of how they > go about their business. What is needed, in short, is more support for > research on intellectual variation and development, and less political > restraint on engaging in it and then applying its findings. > > Second, we should be conscious of how public policy interacts not just with > education but also with other influences on the intellectual quality of the > population, such as the differential in the fertility rates of women of > different intelligence. Many things may be done short of the horrors of The > Handmaid's Tale. Nothing is more private than the decision to bear children, > yet society has a vital interest in the aggregate effects of those > decisions. This issue demands informed public consideration, and probably > also public action to lessen the tension between parenthood and career. At > the very least, we should stop telling bright young women that they make > poor use of their lives by bearing and raising children, as commencement > speakers and others have implied to educated women for decades. > > The competing ideals of equality and efficiency create a dilemma of long > standing. For various reasons, the dilemma is keenly felt in America. The > goal of efficient production competes with the goal of a more equal > distribution of wealth. We can, we believe, gain greater equality with > little or no cost in productive efficiency, especially by investing more in > education. But the data now tell us that economic efficiency depends on > still intractable individual characteristics, given current methods of > education. The individual characteristics run in families for reasons not > easily overridden by social policy. Whatever else we may want to infer from > that fact, we ought to bear in mind that in not too many generations > differential fertility could swamp the effects of anything else we may do > about our economic standing in the world. > > >
