Cognitive Class and Education, 1900-1990

In the course of the twentieth century, America opened the doors of its colleges wider than any previous generation of Americans, or other society in history, could have imagined possible. This democratization of higher education has raised new, barriers between people that may prove to be more divisive and intractable than the old ones.

The growth in the proportion of people getting college degrees is the most obvious result, with a fifteen-fold increase from 1900 to 1990. Even more important, the students going to college were being selected ever more efficiently for their high IQ. The crucial decade was the 1950s, when the percentage of top students who went to college rose by more than it had in the preceding three decades. By the beginning of the 1990s, about 80 percent of all students in the top quartile of ability continued to college after high school. Among the high school graduates in the top few percentiles of cognitive ability the chances of going to college already exceeded 90 percent.

Perhaps the most important of all the changes was the transformation of America's elite colleges. As more bright youngsters went off to college, the colleges themselves began to sort themselves out. Starting in the 1950s, a handful of restitutions became magnets for the very brightest of each year's new class. In these schools, the cognitive level of the students rose far above the rest of the college population.

Taken together, these trends have stratified America according to cognitive ability.

A perusal of Harvard's Freshman Register for 1952 shows a class looking very much as Harvard freshman classes had always looked. Under the photographs of the well-scrubbed, mostly East Coast, overwhelmingly white and Christian young men were home addresses from places like Philadelphia's Main Line, the Upper East Side of New York, and Boston's Beacon Hill. A large proportion of the class came from a handful of America's most exclusive boarding schools; Phillips Exeter and Phillips Andover alone contributed almost 10 percent of the freshmen that year.

And yet for all its apparent exclusivity, Harvard was not so hard to get into in the fall of 1952. An applicant's chances of being admitted were about two out of three, and close to 90 percent if his father had gone to Harvard. With this modest level of competition, it is not surprising to learn that the Harvard student body was not uniformly brilliant. In fact, the mean SAT-Verbal score of the incoming freshmen class was only 583, well above the national mean but nothing to brag about. Harvard men came from a range of ability that could be duplicated in the top half of many state universities.

Let us advance the scene to 1960. Wilbur J. Bender, Harvard's dean of admissions, was about to leave his post and trying to sum up for the board of overseers what had happened in the eight years of his tenure. "The figures," he wrote, "report the greatest change in Harvard admissions, and thus in the Harvard student body, in a short time -- two college generations -- in our recorded history." Unquestionably, suddenly, but for no obvious reason, Harvard had become a different kind of place. The proportion of the incoming students from New England had dropped by a third. Public school graduates now outnumbered private school graduates. Instead of rejecting a third of its applicants, Harvard was rejecting more than two-thirds -- and the quality of those applicants had increased as well, so that many students who would have been admitted in 1952 were not even bothering to apply in 1960.

The SAT scores at Harvard had skyrocketed. In the fall of 1960, the average verbal score was 678 and the average math score was 695, an increase of almost a hundred points for each test. The average Harvard freshman in 1952 would have placed in the bottom 10 percent of the incoming class by 1960. In eight years, Harvard had been transformed from a school primarily for the northeastern socioeconomic elite into a school populated by the brightest of the bright, drawn from all over the country.

The story of higher education in the United States during the twentieth century is generally taken to be one of the great American success stories, and with good reason. The record was not without blemishes, but the United States led the rest of the world in opening college to a mass population of young people of ability, regardless of race, color, creed, gender, and financial resources.

But this success story also has a paradoxically shadowy side, for education is a powerful divider and classifier. Education affects income, and income divides. Education affects occupation, and occupations divide. Education affects tastes and interests, grammar and accent, all of which divide. When access to higher education is restricted by class, race, or religion, these divisions cut across cognitive levels. But school is in itself, more immediately and directly than any other institution, the place where people of high cognitive ability excel and people of low cognitive ability fail. As America opened access to higher education, it opened up as well a revolution in the way that the American population sorted itself and divided itself. Three successively more efficient sorting processes were at work: the college population grew, it was recruited by cognitive ability more efficiently, and then it was further sorted among the colleges.

THE COLLEGE POPULATION GROWS

A social and economic gap separated high school graduates from college graduates in 1900 as in 1990; that much is not new. But the social md economic gap was not accompanied by much of a cognitive gap, became the vast majority of the brightest people in the United States had not gone to college. We may make that statement despite the lack of IQ scores from 1900 for the same reason that we can make such statements about Elizabethan England: It is true by mathematical necessity. In 1900, only about 2 percent of 23-year-olds got college degrees. Even if all of the 2 percent who went to college had IQs of 115 and above (and they did not), seven out of eight of the brightest 23-year-olds in the America of 1900 would have been without college degrees. This situation barely changed for the first two decades of the new century. Then, at the close of World War I, the role of college for American youths began an expansion that would last until 1974, interrupted only by the Great Depression and World War II.

The three lines in the figure show trends established in 1920-1929, 1935-1940, and 1954-1973, then extrapolated. They are there to highlight the three features of the figure worth noting. First, the long perspective serves as a counterweight to the common belief that the college population exploded suddenly after World War II. It certainly exploded in the sense that the number of college students went from a wartime trough to record highs, but this is because two generations of college students were crowded onto campuses at one time. In terms of trendlines, World War II and its aftermath was a blip, albeit a large blip. When this anomalous turmoil ended in the mid-1950s, the proportion of people getting college degrees was no higher than would have been predicted from the trends established in the 1920s or the last half of the 1930s (which are actually a single trend interrupted by the worst years of the depression).

The second notable feature of the figure is the large upward tilt in the trendline from the mid-1950s until 1974. That it began when it did -- the Eisenhower years -- comes as a surprise. The GI bill's impact had faded and the postwar baby boom had not yet reached college age. Presumably postwar prosperity had something to do with it, but the explanation cannot be simple. The slope remained steep in periods as different as Eisenhower's late 1950s, LBJ's mid-1960s, and Nixon's early 1970s.

After 1974 came a peculiar plunge in college degrees that lasted until 1981 -- peculiar because it occurred when the generosity of scholarships and loans, from colleges, foundations, and government alike, was at its peak. This period of declining graduates was then followed by a steep increase from 1981 to 1990 -- also peculiar, in that college was becoming harder to afford for middle-class Americans during those years. As of 1990, the proportion of students getting college degrees had more than made up for the losses during the 1970s and had established a new record, with B.A.s and B.S.s being awarded in such profusion that they amounted to 30 percent of the 23-year-old population.

MAKING GOOD ON THE IDEAL OF OPPORTUNITY

At first glance, we are telling a story of increasing democracy and intermingling, not of stratification. Once upon a time, the college degree was the preserve of a tiny minority; now almost a third of each new cohort of youths earns it. Surely, it would seem, this must mean that a broader range of people is going to college -- including people with a broader, not narrower, range of cognitive ability. Not so. At the same time that many more young people were going to college, they were also being selected ever more efficiently by cognitive ability.

A compilation of the studies conducted over the course of the century suggests that the crucial decade was the 1950s. The next figure shows the data for the students in the top quartile (the top 25 percent) in ability and is based on the proportion of students entering college (though not necessarily finishing) in the year following graduation from high school.

Again, the lines highlight trends set in particular periods, here 1925-1950 and 1950-1960. From one period to the next, the proportion of bright students getting to college leaped to new heights. There are two qualifications regarding this figure. First, it is based on high school graduates -- the only data available over this time period -- and therefore drastically understates the magnitude of the real change from the 1920s to the 1960s and thereafter, because so many of the top quartile in ability never made ...