The End of Average

Todd Rose, director of the Mind, Brain, and Education program at the Harvard Graduate School of Education, argues that the concept of "average" is a scientifically flawed tool for understanding individuals and that society's reliance on averages in schools, workplaces, and research has systematically suppressed human potential. Drawing on history, science, and his own experience as a high school dropout who eventually joined the Harvard faculty, Rose presents three principles of individuality as an alternative framework.

Rose opens with a crisis that struck the U.S. Air Force in the late 1940s: pilots were losing control of their planes at an alarming rate, with seventeen crashing in a single day. Engineers found no mechanical defects, and officials blamed "pilot error" (1). The Air Force then authorized a study measuring more than 4,000 pilots on 140 physical dimensions to update cockpit design, which had been built around the average pilot's body. Lieutenant Gilbert S. Daniels, a junior researcher skeptical of averages from his undergraduate work on hand measurements, calculated the average of the ten dimensions most relevant to cockpit design and found that zero out of 4,063 pilots fell within the average range on all ten. There was no such thing as an average pilot. The Air Force embraced this conclusion, demanded adjustable cockpits, and pilot performance improved dramatically.

Rose traces the origins of averagarian thinking to Adolphe Quetelet, a Belgian mathematician who, after the revolution of 1830 derailed his astronomy career, applied astronomical methods to human society. Astronomers had used the "method of averages" to approximate the true value of celestial measurements. Quetelet applied this logic to people, declaring that individual measurements represented naturally occurring "error" while the average represented a perfect template he called the "Average Man." He computed averages of every human attribute he could find, from body dimensions to crime rates, and his ideas spread widely, influencing government censuses and thinkers from Florence Nightingale to Karl Marx. Francis Galton, a wealthy British mathematician, modified Quetelet's framework. Galton agreed that the average was scientifically foundational but rejected it as an ideal. For Galton, to be average was to be mediocre. He recast deviation from the average not as error but as rank and claimed that rank was consistent across all qualities: Someone eminent in intelligence would likely be eminent in character too. Rose labels these two assumptions, Quetelet's idea that the average indexes normality and Galton's idea that rank reveals talent, the twin pillars of what he calls the Age of Average.

Frederick Winslow Taylor translated these ideas into the dominant organizational philosophy of the modern workplace. Taylor standardized factory processes by measuring average completion times and motions, insisted there was always "one best way" (44) to perform any task, and introduced the manager as a planner who would oversee workers. His 1911 book The Principles of Scientific Management became an international bestseller. Taylorist principles soon reshaped education: Schools adopted age-based grouping, fixed class periods, and bells modeled on factories. Edward Thorndike, one of the era's most prolific psychologists, argued that schools should sort students by innate ability. He created standardized tests and entrance exams that gave rise to gifted programs, honors tracks, and GPA-based ranking. Rose acknowledges that the Taylorization of schools and workplaces was not entirely harmful; it raised wages, reduced nepotism, and increased high school graduation rates from six percent to 81 percent. However, it came at the cost of individual dignity and uniqueness.

The book's turning point comes with Peter Molenaar, a Dutch mathematical psychologist who spent his career committed to averagarianism. While rereading Statistical Theories of Mental Test Scores (1968) by Frederic Lord and Melvin Novick, Molenaar recognized a fundamental error. Lord and Novick acknowledged that finding an individual's "true score" required testing the same person many times, but since learning made repeated testing impractical, they substituted a group's score distribution for an individual's. Molenaar saw that ergodic theory, a branch of mathematics originally developed by physicists studying gas molecules, specifies that group averages can predict individual behavior only if every group member is identical and unchanging. Human beings obviously fail both conditions. Molenaar called this substitution the "ergodic switch," and in a 2004 manifesto he declared averagarianism irredeemably wrong. He later founded a research group at Penn State University dedicated to a science of the individual. This approach, which Rose calls "analyze, then aggregate," studies patterns within each person before looking for collective insights. Rose illustrates its power through developmental psychologist Esther Thelen's study of the infant stepping reflex, in which newborns exhibit a walking-like motion that vanishes around two months. The long-accepted explanation, derived from averaged data, attributed the disappearance to neural maturation. By studying forty babies individually, Thelen discovered the real cause: Infants whose legs gained fat faster than muscle lost the reflex earlier because their muscles could not support the added weight. Averaging had erased each child's individual developmental pattern and concealed the true explanation.

Rose then presents three principles of individuality. The jaggedness principle holds that meaningful human qualities consist of multiple dimensions that are weakly correlated, making one-dimensional ranking misleading. Daniels's study showed that no pilot was average on all ten cockpit-relevant dimensions. Google discovered that SAT scores, alma mater prestige, and grades were not predictive of employee success, and no single variable mattered for most jobs. Rose illustrates jaggedness through the New York Knicks, who assembled the NBA's highest combined scoring average by evaluating players solely on points per game and then suffered four straight losing seasons because basketball talent requires multiple weakly correlated skills.

The context principle asserts that behavior emerges from the interaction between the individual and the situation, not from fixed traits. University of Washington professor Yuichi Shoda tracked 84 children at a residential summer camp and found that each child exhibited different behaviors in different contexts. Shoda proposed "if-then signatures" as an alternative to trait-based labels: Rather than calling someone extroverted, one should specify the contexts that elicit extroverted behavior. Celeste Kidd's follow-up to Walter Mischel's well-known marshmallow study, in which children were tested on their ability to delay eating a treat, reinforced this point by showing that children's self-control depended heavily on whether they were in a reliable or unreliable environment.

The pathways principle holds that there are many equally valid ways to reach the same outcome, a concept known in systems theory as equifinality, and that the optimal pathway depends on the individual. Karen Adolph tracked 28 infants and found 25 different pathways to crawling, all leading to walking. Benjamin Bloom's experiments showed that when students learned at their own pace, more than 90 percent achieved mastery, compared to roughly 20 percent in fixed-pace instruction. Rose describes his own unorthodox university pathway: skipping remedial math by passing a onetime test, postponing freshman English until senior year, and taking advanced courses first.

Rose demonstrates how three companies have succeeded by committing to individuality. Costco pays well above the retail industry average and promotes heavily from within, achieving turnover of 17 percent versus Walmart's approximately 40 percent; when hidden turnover costs are factored in, Costco actually pays less per employee. Zoho Corporation, India's largest IT products company, created an internal university recruiting economically disadvantaged youngsters and training them through self-paced, gradeless instruction. Morning Star Company, the world's largest tomato-processing company, operates with no managers and no hierarchy, with each employee drafting a personal mission statement and being held accountable by peers.

Rose proposes transforming higher education by replacing diplomas with stackable credentials certifying specific skills, replacing grades with competency-based evaluation, and letting students determine their own educational pathways. He concludes with Colonel Kim N. Campbell, a five-foot-four, 120-pound pilot who manually landed a severely damaged A-10 Warthog military aircraft in 2003, a feat possible only because the Air Force had adopted adjustable cockpits that fit her body. Rose argues that Campbell's story illustrates "equal fit": If the environment matches our individuality, we can show what we are truly capable of. Invoking James Truslow Adams's original 1931 formulation of the American Dream as a vision in which each person can "attain to the fullest stature of which they are innately capable, and be recognized by others for what they are" (189), Rose contends that the principles of individuality offer a practical path to restoring that vision.