Discrimination and Disparities


By Thomas Sowell

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An enlarged edition of Thomas Sowell’s brilliant examination of the origins of economic disparities

Economic and other outcomes differ vastly among individuals, groups, and nations. Many explanations have been offered for the differences. Some believe that those with less fortunate outcomes are victims of genetics. Others believe that those who are less fortunate are victims of the more fortunate.

Discrimination and Disparities gathers a wide array of empirical evidence to challenge the idea that different economic outcomes can be explained by any one factor, be it discrimination, exploitation, or genetics. This revised and enlarged edition also analyzes the human consequences of the prevailing social vision of these disparities and the policies based on that vision–from educational disasters to widespread crime and violence.



The first edition of this book addressed the seemingly invincible fallacy that statistical disparities in socioeconomic outcomes imply either biased treatment of the less fortunate or genetic deficiencies in the less fortunate. This edition takes on other widespread fallacies, including a non sequitur underlying the prevailing social vision of our time—namely, that if individual economic benefits are not due solely to individual merit, there is justification for having politicians redistribute those benefits.

Each fallacy seems plausible on the surface, but that is what makes it worthwhile to scrutinize both their premises and the underlying facts. Many other new issues are addressed in this edition—in an international context, as in the first edition—but these two fallacies seem to be at the heart of much, if not most, of the prevailing social vision, sometimes summarized as “social justice.”

Disagreements about social issues in general seem to be not only inevitable but even beneficial, when opposing sides are forced to confront contrary arguments that might not have been considered before, and examine empirical evidence not confronted before. Neither side may have taken all the factors into consideration, but having to cope with each other’s different views may bring out considerations that neither side gave much thought to at the outset.

Such searching re-examinations of opposing views have become all too rare in politics, in the media and even in academia, where the proud claim was once made that “We are here to teach you how to think, not what to think.” Today, with whole academic departments devoted to promoting particular conclusions about social issues, it seems especially important that such re-examinations of conflicting views take place somewhere, lest we become a people easily stampeded by rhetoric, garnished with a few arbitrarily selected facts or numbers.

Those readers who are looking for policy “solutions” will not find them here. But there are ample, if not more than ample, sources of feel-good “solutions” available elsewhere. The goal of Discrimination and Disparities will be met if it can provide clarification on some major social issues that are too often mired in dogmas and obfuscation. Individuals can then decide what policies suit their own values and goals. As Daniel Patrick Moynihan once said: “You’re entitled to your own opinion, but you’re not entitled to your own facts.”1

Thomas Sowell

The Hoover Institution

Stanford University

Chapter 1

Disparities and Prerequisites

Large disparities in the economic and other outcomes of individuals, groups and nations have produced reactions ranging from puzzlement to outrage. Attempts to explain the causes of these disparities have likewise produced a wide range of responses. At one end of a spectrum of explanations offered is the belief that those who have been less fortunate in their outcomes are genetically less capable. At the other end of the spectrum is the belief that those less fortunate are victims of other people who are more fortunate.

In between, there are many other explanations offered. But, whatever the particular explanation offered, there seems to be general agreement that the disparities found in the real world differ greatly from what might be expected by random chance. Yet the disparities in outcomes found in economic and other endeavors need not be due to either comparable disparities in innate capabilities or comparable disparities in the way people are treated by other people.

The disparities can also reflect the plain fact that success in many kinds of endeavors depends on prerequisites peculiar to each endeavor—and a relatively small difference in meeting those prerequisites can mean a very large difference in outcomes.


The effect of prerequisites on probabilities is very straightforward. When there is some endeavor with five prerequisites for success, then by definition the chances of success in that endeavor depend on the chances of having all five of those prerequisites simultaneously. These prerequisites need not be rare in order to produce skewed distributions of outcomes. For example, if these prerequisites are all so common that chances are two out of three that any given person has any one of those five prerequisites, nevertheless the odds are against having all five of the prerequisites for success in that endeavor.

When the chances of having any one of the five prerequisites are two out of three, as in this example, the chance of having all five simultaneously is two-thirds multiplied by itself five times. That comes out to be 32/243 in this example,1 or about one out of eight. In other words, the chances of failure are about seven out of eight. All those people with fewer than five prerequisites have the same outcome—failure. Only those with all five of those prerequisites succeed. This creates a very skewed distribution of success, and nothing like a normal bell curve of distribution of outcomes that we might expect otherwise.2

What does this little exercise in arithmetic mean in the real world? One conclusion is that we should not expect success to be evenly or randomly distributed among individuals, groups, institutions or nations in endeavors with multiple prerequisites—which is to say, most meaningful endeavors. And if these are indeed prerequisites, then having four out of five prerequisites means nothing, as far as successful outcomes are concerned. In other words, people with most of the prerequisites for success may nevertheless be utter failures.

Whether a prerequisite that is missing is complex or simple, its absence can negate the effect of all the other prerequisites that are present. If you are illiterate, for example, all the other good qualities that you may have in abundance count for nothing in many, if not most, careers today. As late as 1950, more than 40 percent of the world’s adult population were still illiterate. That included more than half the adults in Asia and Africa.3

If you are not prepared to undergo the extended toil and sacrifice that some particular endeavor may require, then despite having all the native potential for great success in that endeavor, and with all the doors of opportunity wide open, you can nevertheless become an utter failure.

Not all the prerequisites are necessarily within the sole control of the individual who has them or does not have them. Even extraordinary capacities in one or some of the prerequisites can mean nothing in the ultimate outcome.

Back in the early twentieth century, for example, Professor Lewis M. Terman of Stanford University launched a research project that followed 1,470 people with IQs of 140 and above for more than half a century. Data on the careers of men in this group—from an era when full-time careers for women were less common4—showed serious disparities even within this rare group, all of whom had IQs within the top one percent.

Some of these men had highly successful careers, others had more modest achievements, and about 20 percent were clearly disappointments. Of 150 men in this least successful category, only 8 received a graduate degree, and dozens of them received only a high school diploma. A similar number of the most successful men in Terman’s group received 98 graduate degrees5—more than a tenfold disparity among men who were all in the top one percent in IQ.

Meanwhile, two men who were tested in childhood, and who failed to make the 140 IQ cutoff level, later earned Nobel Prizes in physics—while none of those men with IQs of 140 and above received a Nobel Prize in any field.6 Clearly, then, all the men in Terman’s group had at least one prerequisite for that extraordinary achievement—namely, a high enough IQ. And, equally clearly, there must have been other prerequisites that none of the hundreds of these men with IQs in the top one percent had.

As for factors behind differences in educational and career outcomes within Terman’s group, the biggest differentiating factor was in family backgrounds. Men with the most outstanding achievements came from middle-class and upper-class families, and were raised in homes where there were many books. Half of their fathers were college graduates, at a time when that was far more rare than today.7

Among those men who were least successful, nearly one-third had a parent who had dropped out of school before the eighth grade.8 Even extraordinary IQs did not eliminate the need for other prerequisites.

Sometimes what is missing may be simply someone to point an individual with great potential in the right direction. An internationally renowned scholar once mentioned, at a social gathering, that when he was a young man he had not thought about going to college—until someone else urged him to do so. Nor was he the only person of exceptional ability of whom that was true.9

Some other people, including people without his great abilities, would automatically apply to college if they came from particular social groups where that was a norm. But without that one person who urged him to seek higher education, this particular internationally renowned scholar might well have become a good worker in some line of work requiring no college degree, but not a world-class scholar.

There may be more or less of an approximation of a normal bell curve, as far as how many people have any particular prerequisite, and yet a very skewed distribution of success, based on having all the prerequisites simultaneously. This is not only true in theory, empirical evidence suggests that it is true also in practice.

In golf, for example, there is something of an approximation of a bell curve when it comes to the distribution of such examples of individual skills as the number of putts per round of golf, or driving distances off the tee. And yet there is a grossly skewed distribution of outcomes requiring a whole range of golf skills—namely, winning Professional Golfers’ Association (PGA) tournaments.10

Most professional golfers have never won a single PGA tournament in their entire lives,11 while just three golfers—Arnold Palmer, Jack Nicklaus and Tiger Woods—won more than 200 PGA tournaments between them.12 Moreover, there are similarly skewed distributions of peak achievements in baseball and tennis, among other endeavors.13

Given multiple prerequisites for many human endeavors, we should not be surprised if economic or social advances are not evenly or randomly distributed among individuals, groups, institutions or nations at any given time. Nor should we be surprised if the laggards in one century forge ahead in some later century, or if world leaders in one era become laggards in another era. When the gain or loss of just one prerequisite can turn failure into success or turn success into failure, it should not be surprising, in a changing world, if the leaders and laggards of one century or millennium exchange places in some later century or millennium.

If the prerequisites themselves change over time, with the development of new kinds of endeavors, or if advances in human knowledge revolutionize existing endeavors, the chance of a particular pattern of success and failure becoming permanent may be greatly reduced.

Perhaps the most revolutionary change in the evolution of human societies was the development of agriculture—within the last 10 percent of the existence of the human species. Agriculture made possible the feeding of concentrated populations in cities, which in turn have been (and remain) the sources of most of the landmark scientific, technological and other advances of the human race that we call civilization.14

The earliest known civilizations arose in geographic settings with strikingly similar characteristics. These included river valleys subject to annual floodings, whether in ancient Mesopotamia, in the valley of the Indus River on the Indian subcontinent in ancient times, along the Nile in ancient Egypt, or in the Yellow River valley in ancient China.15

Clearly there were other prerequisites, since these particular combinations of things had not produced agriculture, or civilizations dependent on agriculture, for most of the existence of the human species. Genetic characteristics peculiar to the races in these particular locations hardly seem likely to be the key factor, since the populations of these areas are by no means in the forefront of human achievements today.

Patterns of very skewed distributions of success have long been common in the real world—and such skewed outcomes contradict some fundamental assumptions on both the political left and right. People on opposite sides of many issues may both assume a background level of probabilities that is not realistic.

Yet that flawed perception of probabilities—and the failure of the real world to match expectations derived from that flawed perception—can drive ideological movements, political crusades and judicial decisions, up to and including decisions by the Supreme Court of the United States, where “disparate impact” statistics, showing different outcomes for different groups, have been enough to create a presumption of discrimination.

In the past, similar statistical disparities were enough to promote genetic determinism, from which came eugenics, laws forbidding inter-racial marriages and, where there were other prerequisites for monumental catastrophe, the Holocaust.

In short, gross disparities among peoples in their economic outcomes, scientific discoveries, technological advances and other achievements have inspired efforts at explanation that span the ideological spectrum. To subject these explanations to the test of facts, it may be useful to begin by examining some empirical evidence about disparities among individuals, social groups, institutions and nations.


Behind many attempts to explain, and change, glaring disparities in outcomes among human beings is the implicit assumption that such disparities would not exist without corresponding disparities in either people’s genetic makeup or in the way they are treated by other people. These disparities exist both among individuals and among aggregations of people organized into institutions of various sorts, ranging from families to businesses to whole nations.

Skewed distributions of outcomes are also common in nature, in outcomes over which humans have no control, ranging from lightning to earthquakes and tornadoes.


While it might seem plausible that equal, or at least comparable, outcomes would exist among people in various social groups, in the absence of some biased human intervention, or some genetic differences affecting those people’s outcomes, neither belief survives the test of empirical evidence.

A study of National Merit Scholarship finalists, for example, found that, among finalists from five-child families, the first-born was the finalist more often than the other four siblings combined.16 Firstborns were also a majority of the finalists in two-child, three-child, and four-child families.17 If there is not equality of outcomes among people born to the same parents and raised under the same roof, why should equality of outcomes be expected—or assumed—when conditions are not nearly so comparable?

Such results are a challenge to believers in either heredity or environment, as those terms are conventionally used.

IQ data from Britain, Germany and the United States showed that the average IQ of first-born children was higher than the average IQ of their later-born siblings. Moreover, the average IQ of second-born children as a group was higher than the average IQ of third-born children.18

A similar pattern was found among young men given mental tests for military service in the Netherlands. The first-born averaged higher mental test scores than their siblings, and the other siblings likewise averaged higher scores than those born after them.19 Similar results were found in mental test results for Norwegians.20 The sample sizes in these studies ranged into the hundreds of thousands.21

These advantages of the first-born seem to carry over into later life in many fields. Data on male medical students at the University of Michigan, class of 1968, showed that the proportion of first-born men in that class was more than double the proportion of later-born men as a group, and more than ten times the proportion among men who were fourth-born or later.22 A 1978 study of applicants to a medical school in New Jersey showed the first-born over-represented among the applicants, and still more so among the successful applicants.23 Other studies, some going as far back as the nineteenth century, show similar results.24

Most other countries do not have as high a proportion of their young people go on to a college or university education as in the United States. But, whatever the proportion in a given country, the first-born tend to go on to higher education more often than do later siblings. A study of Britons in 2003 showed that 22 percent of those who were the eldest child went on to receive a degree, compared to 11 percent of those who were the fourth child and 3 percent of those who were the tenth child.25

A study of more than 20,000 young people in late twentieth-century France showed that 18 percent of those males who were an only child completed four years of college, compared to 16 percent of male first-born children—and just 7 percent of males who were fifth-born or later born. Among females the disparity was slightly larger. Twenty-three percent who were an only child completed four years of college, compared to 19 percent who were first-born, and just 5 percent of those who were fifth-born or later.26

Birth order differences persist as people move into their careers. A study of about 4,000 Americans concluded that “The decline in average earnings is even more pronounced” than the decline in education between those born earlier and those born later.27 Other studies have shown the first-born to be over-represented among lawyers in the greater Boston area28 and among Members of Congress.29 Of the 29 original astronauts in the Apollo program that put a man on the moon, 22 were either first-born or an only child.30 The first-born and the only child were also over-represented among leading composers of classical music.31

Consider how many things are the same for children born to the same parents and raised under the same roof—race, the family gene pool, economic level, cultural values, educational opportunities, parents’ educational and intellectual levels, as well as the family’s relatives, neighbors and friends—and yet the difference in birth order alone has made a demonstrable difference in outcomes.

Whatever the general advantages or disadvantages the children in a particular family may have, the only obvious advantage that applies only to the first-born, or to an only child, is the undivided attention of the parents during early childhood development.

The fact that twins tend to average several points lower IQs than people born singly32 reinforces this inference. Conceivably, the lower average IQs of twins might have originated in the womb but, when one of the twins is stillborn or dies early, the surviving twin averages an IQ closer to that of people born singly.33 This suggests that with twins, as with other children, the divided or undivided attention of the parents may be key.

In addition to quantitatively different amounts of parental attention available to children born earlier and later than their siblings, there are also qualitative differences in parental attention to children in general, from one social class to another.34 Children of parents with professional occupations have been found to hear an average of 2,100 words per hour, while children from working-class families hear 1,200 words per hour, and children from families on welfare hear 600 words per hour.35 Other studies suggest that there are also qualitative differences in the manner of parent-child interactions in different social classes.36

Against this background, expectations or assumptions of equal or comparable outcomes from children raised in such different ways have no basis. Nor can later different outcomes in schools, colleges or employment be automatically attributed to those who teach, grade or hire them, when empirical evidence shows that how people were raised can affect how they turn out as adults.

It is not simply that youngsters raised in different ways may have different levels of ability as adults. People from different social backgrounds may also have different goals and priorities—a possibility paid little or no attention in many studies that measure how much opportunity there is by how much upward movement takes place,37 as if everyone is equally striving to move up, and only society’s barriers produce different outcomes.

Most notable achievements involve multiple factors—beginning with a desire to succeed in the particular endeavor, and a willingness to do what it takes, without which all the native ability in an individual and all the opportunity in a society mean nothing, just as the desire and the opportunity mean nothing without the ability.

What this suggests, among other things, is that an individual, a people, or a nation may have some, many or most of the prerequisites for a given achievement without having any real success in producing that achievement. And yet that individual, that people or that nation may suddenly burst upon the scene with spectacular success when whatever the missing factor or factors are finally get added to the mix.

Poor and backward nations that suddenly moved to the forefront of human achievements include Scotland, beginning in the eighteenth century, and Japan beginning in the nineteenth century. Both had rapid rises, as time is measured in history.

Scotland was for centuries one of the poorest, most economically and educationally lagging nations on the outer fringes of European civilization. There was said to be no fourteenth-century Scottish baron who could write his own name.38 And yet, in the eighteenth and nineteenth centuries, a disproportionate number of the leading intellectual figures in Britain were of Scottish ancestry—including James Watt in engineering, Adam Smith in economics, David Hume in philosophy, Joseph Black in chemistry, Sir Walter Scott in literature and John Stuart Mill in economics and philosophy.

Among the changes that had occurred among the Scots was their Protestant churches’ crusade promoting the idea that everyone should learn to read, so as to be able to read the Bible personally, rather than have priests tell them what it says and means. Another change was a more secular, but still fervent, crusade to learn the English language, which replaced their native Gaelic among the Scottish lowlanders, and thereby opened up far more fields of written knowledge to the Scots.

In some of those fields, including medicine and engineering, the Scots eventually excelled the English, and became renowned internationally. These were mostly Scottish lowlanders, rather than highlanders, who continued to speak Gaelic for generations longer.

Japan was likewise a poor, poorly educated and technologically backward nation, as late as the middle of the nineteenth century. The Japanese were astonished to see a train for the first time, that train being presented to them by American Commodore Matthew Perry, whose ships visited Japan in 1853.39 Yet, after later generations of extraordinary national efforts to catch up with the Western world technologically, these efforts led to Japan’s being in the forefront of technology in a number of fields in the latter half of the twentieth century. Among other things, Japan produced a bullet train that exceeded anything produced in the United States.

Other extraordinary advances have been made by a particular people, rather than by a nation state. We have become so used to seeing numerous world-class performances by Jewish intellectual figures in the arts and sciences that it is necessary to note that this has been an achievement that burst upon the world as a widespread social phenomenon in the nineteenth and twentieth centuries, even though there had been isolated Jewish intellectual figures of international stature in some earlier centuries.

As a distinguished economic historian put it: “Despite their vast advantage in literacy and human capital for many centuries, Jews played an almost negligible role in the history of science and technology before and during the early Industrial Revolution.” Moreover, “the great advances in science and mathematics between 1600 and 1750 do not include work associated with Jewish names.”40

Whatever the potentialities of Jews during the era of the industrial revolution, and despite their literacy and other human capital, there was often little opportunity for them to gain access to the institutions of the wider society in Europe, where the industrial revolution began. Jews were not admitted to most universities in Europe prior to the nineteenth century.

Late in the eighteenth century, the United States became a pioneer in granting Jews the same legal rights as everyone else, as a result of the Constitution’s general ban against federal laws that discriminate on the basis of religion. France followed suit after the revolution of 1789, and other nations began easing or eliminating various bans on Jews in various times and places during the nineteenth century.

In the wake of these developments, Jews began to flow, and then to flood, into universities. By the 1880s, for example, Jews were 30 percent of all the students at Vienna University.41 The net result in the late nineteenth century, and in the twentieth century, was a relatively sudden proliferation of internationally renowned Jewish figures in many fields, including fields in which Jews were virtually non-existent among the leaders in earlier centuries.

From 1870 to 1950, Jews were greatly over-represented among prominent figures in the arts and sciences, relative to their proportion of the population in various European countries and in the United States. In the second half of the twentieth century, with Jews being less than one percent of the world’s population, they received 22 percent of the Nobel Prizes in chemistry, 32 percent in medicine and 32 percent in physics.42

Here, as in other very different contexts, changes in the extent to which prerequisites are met completely can have dramatic effects on outcomes in a relatively short time, as history is measured. The fact that Jews rose dramatically in certain fields after various barriers were removed does not mean that other groups would automatically do the same, if barriers against them were removed, for the Jews already had various other prerequisites for such achievements—notably widespread literacy during centuries when illiteracy was the norm in the world at large—and Jews needed only to add whatever was needed to complete the required ensemble.

Conversely, China was for centuries the most technologically advanced nation in the world, especially during what were called the Middle Ages in Europe. The Chinese had cast iron a thousand years before the Europeans.43 A Chinese admiral led a voyage of discovery that was longer than Columbus’ voyage, generations before Columbus’ voyage,44 and in ships far larger and technologically more advanced than Columbus’ ships.45


  • "Sowell's calm and calculated look at racial disparity in America is a stunning work of brevity and reason."—Federalist
  • "Timely...a must-read."—Rush Limbaugh, The Limbaugh Letter
  • "A sane, balanced and highly informed discussion of many of the central issues of the day."—Washington Times
  • "Everything Dr. Sowell writes is worth reading, but this book couldn't be more timely. If there is any topic that needs a strong dose of empirical data and common sense, it is this one."—Power Line
  • "[Sowell] writes on economics in a manner that is not only accessible, but also relevant and even riveting."—The Conservative Woman
  • "Few works on politically explosive topics maintain such a consistent focus on empirical evidence while avoiding rhetorical jabs at opponents...those who cling to this dogma with religious fervor will likely avoid Sowell's fact-filled book like kryptonite. Folks with less dogmatic proclivities, however, would do well to peruse this concise work."—American Thinker
  • "Throughout his career, Thomas Sowell has been fearless in confronting uncomfortable facts about human nature and ill-conceived public policies. His new book, Discrimination and Disparities, is the latest in a long line of works that calmly but persuasively shatter myths and ideological beliefs about race, ethnicity, economics, history, and culture."—New York Journal of Books
  • “Thomas Sowell’s Discrimination and Disparities is must reading for anyone who wants to understand what drives economic and social inequality among different groups. Sowell has spent a career bringing clarity and insight to heated public policy discussions that too often lack both. And no topic today is more in need of the Sowell treatment than the one surrounding racial and ethnic disparities. You don’t need a Ph.D. to understand this book, and having read it you will be far better informed than most of the academic and media elites sounding off on the subject.”
     —Jason Riley, author of Please Stop Helping Us and False Black Power?
  • “In this provocative book, Thomas Sowell turns the tables on those who automatically link disparate outcomes to discrimination. He begins by focusing instead on the myriad of factors that need to come together for success. Before we can explain why people fall behind in life, we must first understand what life demands for success…. Native intelligence by itself does not guarantee success. Hard work is important, but nature can be capricious. Who knew that being first born is a persistent factor for success in life? The book is chock full of such pertinent observations, none of which reflect discrimination by anyone. The book is a wonderful short introduction to the thought of one of our most important social thinkers.”—Gerald P. O’Driscoll, Jr., Senior Fellow, CATO Institute

On Sale
Mar 5, 2019
Page Count
320 pages
Basic Books

Thomas Sowell

About the Author

Thomas Sowell is a Senior Fellow at the Hoover Institution, Stanford University. For more than half a century, his writings have appeared in both popular and scholarly publications, on both sides of the Atlantic, and his books have been translated into a dozen foreign languages. After a career as an economist in the government, academia and the corporate world, he has since 1980 been a scholar in residence at the Hoover Institution, devoting his efforts to research and writing, on subjects ranging from the history and influence of intellectuals to education and social policies in countries around the world. His website is http://www.tsowell.com.

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