Chapter 15- The demography of Intelligence

When people die they are not replaced one for one by babies who have identical IQs. If the next generation of babies grows up with systematically higher or lower IQs, the national distribution of IQ changes. The evidence indicates that demographic trends are exerting downward pressure on the distribution of cognitive ability and that these pressures are strong enough to have significant social consequences. Throughout the western world modernization has brought falling birth rates. More importantly, the birth rates are falling faster for educated women than the uneducated. Furthermore, education leads women to have their babies later, which also produces additional dysgenic pressures.

Current immigration policies provide the other major source of dysgenic pressure. The mean IQ of immigrants in the 1980s was about 95. This in itself may not be much of a problem; in the past, immigrants have shown large increases in such measures after a few generations. But the evidence indicates that the self-selection process that used to attract the classical American immigrant- brave, hard working, imaginative, self-starting and often high IQ- has been changing and with it the nature of the immigrant population. Putting the pieces together, something worrying is happening to the cognitive capital of the country. Whatever good things we can accomplish with changes in the environment would be much more effective if they did not have to fight these demographic head winds. As the population replenishes itself from generation to generation by birth and immigration, the people who pass from the scene are not going to be replaced, one for one, by people with the same IQ scores. This is what the authors mean by the demography of intelligence. The question is not whether the demographic processes themselves can have an impact on the distribution of intelligence, that much is for certain, but what and how big the impact is. Mounting evidence indicates that that these demographic changes in the mean national IQ are exerting downward pressures that are significant enough to have major negative social and economic consequences. The authors refer to this downward pressure as dysgenesis. Children resemble their parents, for whatever reason, in IQ and immigrants with low IQs and their decedents will not duplicate America's resident cognitive ability distribution. If women with low scores are producing more rapidly that women with higher scores the mean IQ of our nation will decline irrespective of whether the women with low scores come by them by nature or nurture. The author's exploration of this all important issue proceeds in three stages. First, they describe the state of knowledge as to when and why dysgenesis occurs. Next they look at the present state of affairs regarding differential birth rates, the effects of differences in the age of childbearing and lastly the effects of immigration. Finally, they speculate on the shape of the future and describe the magnitude of the stakes involved. Hold your hat, we are in for a bumpy and disquieting ride! In pre-modern times, privileged young women were better nourished, better rested and had better medical care than the underprivileged. They married earlier and suffered fewer disruptions. As a result they ended up with more surviving children. As modernization proceeded these advantages narrowed. Modern societies provide greater opportunities for privileged women to be something other than house wives. On average modern women spend more of their reproductive years in school. The cost of raising a child is another reason privileged women bear fewer children and postpone the ones they do bear. Meanwhile, children impose few opportunity costs for poor women because a "career" usually is not seen as a viable option. Children, on the other hand, continue to have the same attractions that have always led young women to find motherhood intrinsically rewarding. Finally, in most countries in the contemporary west a baby is free or even profitable depending on the welfare system in her country. For all these reasons reproductive rates are correlated with income and educational levels, which in turn are correlated with intelligence. What is the evidence that this type of dysgenesis is actually happening? In the 1930s the eminent psychometrician Raymond Cattell was predicting a loss of 1.0 to 1.5 IQ points per generation. Another predicted that "If this trend continued for another century England and America would be well on the way to becoming nations of near half-wits." Their pessimism was based on the fact that the average IQ in large families was lower than in smaller families. However, during the 1960s a number of studies seemed to show that the IQ of the nation was almost stable, or perhaps rising slowly, despite the lower average IQs in larger families. This optimism proved to be ephemeral because the studies were of nearly all white populations in the upper Midwest and, as such, were not representative of the national population. In 1982 demographer Daniel Vining showed that when birth rates were high, people with higher intelligence tended to have more children than those who had lower cognitive ability while in times of falling birth rates the opposite was true. The American fertility rate has been falling since the late 1950s and so have the birth rates of educated white women. Since the flawed studies in the 1960s and 1970s, all the news has been bad. A 1980s study of a nearly all-white sample of people in Wisconsin found a dysgenic effect of 0.8 IQ points a generation. Several other studies have suggested that the 0.8 figure underestimates the actual decrease in IQ that is occurring with each generation. When considering the dysgenic pressures in America there are three major factors to take into account: the numbers of children born to women of various IQ levels, the age at which they have them and, most importantly the cognitive ability of immigrants. First, let's consider the cognitive level of the women who are having children. Demographers take a fertility rate of 2.1 as a dividing line between having enough children to replenish the parent generation and having to few. Overall, women who were college graduates had 1.56 children, one child less than the lower IQ women without even a high school diploma. this means that high school dropouts had 71 percent more children than women who had graduated from college. The overall IQ of American mothers in 1992 was a little less than 98 which suggests a decline in IQ of about 0.8 points per generation. Population growth depends not just on the total number of children women have but on how old they are when they have them. The effect is dysgenic when a low-IQ group has babies at a younger age than the high-IQ group, even if the number born in each group eventually is the same. Suppose that over several generations low and high IQ mothers have the same number of children but the low IQ mothers always have their first baby on their twentieth birthday and all the high IQ mothers have their first baby on their thirtieth birthday. The low IQ mothers will produce three generations of children to every two produced by the high IQ mothers. Studies of fertility rates among ethnic groups tells a similar story. In a 1992 analysis of American fertility women ages 35 to 44 had given birth to an average of 1.94 children; 1.89 for white women,2.23 for black women, and 2.47 for Latino women. More disturbing is the fact that, in all three groups, the more educated the women were the lower were their fertility rates. We cannot conclude, however, that whites, blacks and Latinos are on the same downward slope because each ethnic group has different proportions of women at different IQ levels. For example, black and white women with IQs of 90 or below have similar birth rates but only 15 percent of white women fall in the 90s and below range compared to 52 percent of black women. As of 1992, 69 percent of all black children were born to mothers with IQs of 90 or lower. The figure was 19 percent for whites and 64 percent for Latino mothers with low IQs. Immigration is an even older trip wire for impassioned debate than differential fertility. American has more people flowing into it than any other country. About half of the world's immigrants are coming to America. The nation's political ground rules have yet to accept that the intelligence of immigrants is a legitimate topic for policymakers to consider. To the contrary, politicians on both sides of the isle seem to believe that the IQs of illegal immigrants from Mexico and south America are similar, if not identical, to those of the population already living here. To begin the discussion the authors assume that immigrants to America have similar mean IQs to those living in the countries from which they came. (This is an absurd assumption considering that well educated Mexicans are not among the hordes of illegal's crossing our southern border each day.) Using this rational the average IQ of immigrants in the 1980s was 95- essentially unchanged from the 1950s and 1960s. With respect to ethnic groups, white immigrants have slightly higher mean IQs than the native-born American population, although somewhat lower than native-born American whites. For reasons not known, foreign born black immigrants have IQs five points higher than American born blacks. Finally, Latino immigrants have mean scores more than seven points below native-born Latinos. With respect to IQ, there is no reliable information on the large immigrant population from East Asia and Vietnam, who might be significantly boosting the immigration mean IQ. The United States maybe expected to draw high-ability workers from countries that have more extensive welfare states and less income inequality than we do and will draw low-ability workers from countries that have less extensive welfare states and higher income inequality (such as the poorer countries in the third world). Borjus used the census figures from 1970 and 1980 to examine the experience of immigrants from 41 countries. In the 1960s and 1970s the United states became much more of a welfare state. During this period of time, the earning potential of Latino immigrants fell substantially from 1955 to 1980. Among the non-European countries, the steepest declines in earning potential were among immigrant groups from Columbia, the Dominican Republic and Mexico. Only the immigrant groups from Cuba, Brazil and Panama had improving potential in America, by Borjas's measure. When all is said and done, just how important is dysgenic pressure? The higher fertility rate and faster generational cycle among the less intelligent native born Americans and the immigration population, that is somewhat below the national average, suggests that something worrisome is happening to the cognitive capital of the country. Just how big is this effect? Using the usual metrics for such analysis it would be nearly impossible to make the total fall in the nations cognitive ability less than one IQ point a generation and it might be twice that. But, so what if the nations mean IQ is falling a point or two each generation? One obvious reason is that the drop may be increasing ethnic difference in cognitive ability at a time when the nation badly needs narrowing differences. Another reason to be concerned is that when the mean IQ of the nation shifts a little, the size of the tails of the distribution (the tails of the bell curve for intelligence) change a lot. For example, a three point drop in the mean IQ would reduce the proportion of the population with IQs over 120 to 31 percent and the proportion with IQs above 135 by 41 percent. Similarly the proportion of the population with IQs below 65 (the very dull) would rise by 68 percent. Changes this large would profoundly alter most aspects of American life, none the authors can think of that are good. Even a fall in mean IQ of only three points will have a profound effect on our society. The overall poverty rate will increase by 11 percent and the proportion of children living in poverty will rise by 13 percent. The proportion of children born to single mothers will rise by 8 percent and the numbers of males in jail will increase by 13 percent. The proportion of children living with non-parental custodians, of women forever on welfare, and the number of high school dropouts will all increase by 14 percent. A cascade of secondary effects, all of which were ignored in this analysis, may make social conditions worse than the authors suggest or perhaps not as bad. But the overall point is irrefutable, that relatively minor shifts in the nations mean IQ can produce profound social consequences. So what would happen if the mean IQ of Americans went up three IQ points? For starters, the poverty rate would fall by 25 percent as would the numbers of males in prison. The high school dropout rate would fall by 28 percent. Children living without their parents would decrease by 20 percent and the numbers on welfare would drop by 18 percent. It is easy to understand the historical, social and political reasons why no one wants to talk about the demographics of intelligence. The authors purpose was to point out that the stakes are large (I think huge) and that continuing to pretend that "there is nothing worth thinking about" is as feckless as it is foolish. Comment: The Bell Curve was first published in 1995. During the intervening 20 years the socioeconomic problems have become significantly worse. Seventy two percent of all young black males are either in prison or on parole. The illegitimacy rate is 72 percent for blacks and a whopping 40.7 overall. Over 90 million Americans are out of work. Undoubtedly, these grime statistics are due, at least in part, to the fact that Americans, as a whole, have become increasing dumber with the passage of time, just as the authors predicted. Things could have been done to change the situation, but for political reasons were not. We should have build the damned wall 20 years ago, but did not. We should have reversed course after The Bell Curve was published two decades ago and started paying welfare mothers not to have babies rather than paying them to have babies, but we did not. We should have stopped shipping jobs that low IQ people could perform overseas years ago, but we have not. In short, there are many things we could do to improve the economy and decrease the social problems we are facing in the twenty-first century, but as long as the cabal of big business, who want cheap labor, and liberal democrats, who want a consistent source of low IQ voters, nothing will be done. You can take that to the bank!