Thursday, April 20, 2017


A new book is out called  The End of Average by L. Todd Rose. It asks people to look at the statistics and the averages we are faced with in an entirely different way.
The astounding generalization is "any system designed around the average person is doomed to fail."

In the late 1940s the U.S. Air Force was having a lot of trouble with accidents. On its worst day, 17 pilots crashed in a single 24 hour period.
The only thing they knew for sure was that their piloting skills were not the cause of the problem. Nor were the planes experiencing technical trouble. If it wasn’t human or mechanical error, what was it?
One theory emerged: The size and shape of the seat, the distance to the pedals and stick, the height of the windshield, even the shape of the flight helmets were all built to conform to the average dimensions of a 1926 pilot.
Military engineers began to wonder if the pilots had gotten bigger since 1926 and if this might be a factor in the crashes. To obtain an updated assessment of pilot dimensions, the air force authorized the largest study of pilots that had ever been undertaken. In 1950, researchers at Wright Air Force Base in Ohio measured more than 4,000 pilots on 140 dimensions of size, including thumb length, crotch height, and the distance from a pilot’s eye to his ear, and then calculated the average for each of these dimensions.

To address this question The Aero Medical Laboratory hired Lt. Gilbert S. Daniels because he had majored in physical anthropology, a field that specialized in the anatomy of humans, as an undergraduate at Harvard.
His undergraduate thesis consisted of a rather plodding comparison of the shape of 250 male Harvard students’ hands. The students Daniels examined were from very similar ethnic and socio-cultural backgrounds (namely, white and wealthy), but, unexpectedly, their hands were not similar at all. Even more surprising, when Daniels averaged all his data, the average hand did not resemble any individual’s measurements. There was no such thing as an average hand size. “When I left Harvard, it was clear to me that if you wanted to design something for an individual human being, the average was completely useless,” Daniels said.

Using the size data he had gathered from 4,063 pilots, Daniels calculated the average of the 10 physical dimensions believed to be most relevant for design, including height, chest circumference and sleeve length. These formed the dimensions of the “average pilot,” which Daniels generously defined as someone whose measurements were within the middle 30 per cent of the range of values for each dimension. The consensus among his fellow air force researchers was that the vast majority of pilots would be within the average range on most dimensions. After all, these pilots had already been pre-selected because they appeared to be average sized. (If you were, say, six foot seven, you would never have been recruited in the first place.)
Out of 4,063 pilots, not a single airman fit within the average range on all 10 dimensions. One pilot might have a longer-than-average arm length, but a shorter-than-average leg length. Another pilot might have a big chest but small hips. Even more astonishing, Daniels discovered that if you picked out just three of the ten dimensions of size — say, neck circumference, thigh circumference and wrist circumference — less than 3.5 per cent of pilots would be average sized on all three dimensions. Daniels’s findings were clear and incontrovertible. There was no such thing as an average pilot. If you’ve designed a cockpit to fit the average pilot, you’ve actually designed it to fit no one.

Seven years earlier, the Cleveland Plain Dealer announced on its front page a contest co-sponsored with the Cleveland Health Museum and in association with the Academy of Medicine of Cleveland, the School of Medicine and the Cleveland Board of Education. Winners of the contest would get $100, $50, and $25 war bonds, and 10 additional lucky women would get $10 worth of war stamps. The contest? To submit body dimensions that most closely matched the typical woman, “Norma,” as represented by a statue on display at the Cleveland Health Museum known as the “Rodin of obstetrics.” Norma was the creation of a well-known gynecologist, Dr. Robert L. Dickinson, and his collaborator Abram Belskie, who sculpted the figure based on size data collected from 15,000 young adult women.

In addition to displaying the sculpture, the Cleveland Health Museum began selling miniature reproductions of Norma, promoting her as the “Ideal Girl,” launching a Norma craze. Norma was featured in Time magazine, in newspaper cartoons, and on an episode of a CBS documentary series, This American Look, where her dimensions were read aloud so the audience could find out if they, too, had a normal body.
On Nov. 23, 1945, the Plain Dealer announced its winner, a slim brunette theatre cashier named Martha Skidmore. Less than 40 of the 3,864 contestants were average size on just five of the nine dimensions and none of the contestants — not even Martha Skidmore — came close on all nine dimensions. Just as Daniels’ study revealed there was no such thing as an average-size pilot, the Norma Look-Alike contest demonstrated that average-size women did not exist either.

Many concluded that American women, on the whole, were unhealthy and out of shape. One of those critics was the physician Bruno Gebhard, head of the Cleveland Health Museum, who lamented that postwar women were largely unfit to serve in the military, chiding them by insisting “the unfit are both bad producers and bad consumers.” His solution was a greater emphasis on physical fitness. Daniels’ interpretation was the exact opposite. “The tendency to think in terms of the ‘average man’ is a pitfall into which many persons blunder,” Daniels wrote in 1952. “It is virtually impossible to find an average airman not because of any unique traits in this group but because of the great variability of bodily dimensions which is characteristic of all men.”
Rather than suggesting that people should strive harder to conform to an artificial ideal of normality, Daniels’ analysis led him to a counterintuitive conclusion that serves as the cornerstone of this book: any system designed around the average person is doomed to fail.

By discarding the average as their reference standard, the Air Force initiated a quantum leap in its design philosophy, centered on a new guiding principle: individual fit. Rather than fitting the individual to the system, the military began fitting the system to the individual.
Once these and other design solutions were put into place, pilot performance soared, and the U.S. air force became the most dominant air force on the planet. Soon, every branch of the American military published guides decreeing that equipment should fit a wide range of body sizes, instead of standardized around the average. When pilots flying faster than the speed of sound were required to perform tough maneuvers using a complex array of controls, they couldn’t afford to have a gauge just out of view or a switch barely out of reach. In a setting where split-second decisions meant the difference between life and death, pilots were forced to perform in an environment that was already stacked against them.
(from The End of Average by L. Todd Rose)
Norma was designed to represent the "ideal" female form, based on measurements collected from 15,000 young adult women. The statue on display at the Cleveland Health Museum was the creation of a gynecologist, Dr. Robert L. Dickinson, and his collaborator Abram Belskie.

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