Twenty-five years ago, when my wife was studying for her secondary education certificate at Kutztown University, she was required to take a class on how to grade students using the bell-shaped curve.
She asked the instructor, "Why do we have to curve our grades? If the grades were so poor, wouldn't that imply either the students were not learning, the students were not working hard, the test was not testing what it should, or the teacher is not doing a good job. I did not get a satisfactory answer."
According to recent research, there is now a satisfactory answer, and that is that the bell-shaped curve does not apply to the distribution of grades in the classroom. Moreover, it does not apply to the distribution of human performance.
The bell-shaped curve implies that there is a large normal toward the middle of the curve, and a lesser amount toward the outliers. But normal is abnormal, according to The Best and the Rest: Revisiting the Norm of Normality of Individual Performance, a paper published in Personnel Psychology by Ernest O'Boyle Jr. and Herman Aguinis.
In a study that examined the performance of 633,263 people involved in four broad areas of human performance academics writing papers, athletes at the professional and collegiate levels, politicians and entertainers they determined that from professors to sports figures to Emmy and Grammy nominees, about 10 percent are superstars, about 80 percent fall below average, and only about 10 percent cluster around the midpoint.
Just like we see that the top 10 percent of the wealthy in America have about 80 percent of the wealth, and the bottom 80 percent have about 10 percent of the wealth, the same distribution applies to success in school, business, sports and entertainment.
According to National Public Radio, "We expect some people to be very good, some people to be very bad, and everyone else to be in the middle."
The researchers found that most people did not fit the bell-shaped curve.
"Most people are actually below average and a small but fairly sizable number of superstars accounts for most of the performance whether you were talking about home runs, academic papers or Oscar nominations."
"If you look at the universe of Grammy nominations, what you'd expect to see, lots of people would receive three or four nominations, and fewer than five would receive more than 10 nominations. Instead, most people only receive one nomination, and a sizable number, 64 people, received more than 10 nominations."
The bell-shaped curve was originally developed by French mathematician Abraham de Moivre in 1738 to explain the outcomes from games of chance. His work, improved upon by Gauss, Laplace and others, found application to statistical quality control in the workplace.
As industrial engineers moved from the production department to the human relations department, they took the bell-shaped curve with them and applied it to the performance of work on the assembly line.
It worked well to describe workers whose performance was constrained so that, because of the unvarying speed of the assembly line, they could not work too quickly or too slowly. What became successful in the post World War II factories, found their way into the management of education.
It turns out that although a bell-shaped curve is a fair representation of natural phenomena such as the distribution of men's hiking the population, women's weight, or heart disease, it is a poor representation of the distribution of performance.
The research implies that a small number of people are either better, stronger, brighter, more talented, have better genetics, come from wealthier families, have greater motivation or some combination of all these factors plus other unknown factors, together create super achievers.
So, when it comes to the distribution of grades in a school class, does it make any sense to give out a few "A"s, several "B"s, a bunch of "C"s, a few "D"s, and the occasional "F"? One teacher's morning class might have a great number of achievers, and the same teacher's afternoon class may have very few.
Should they have the same distribution of grades?
The researchers said that "successful companies and nations would do well to identify superstars, because such performers were disproportionately likely to register new discoveries and achievements."
For the rest of us, if you've been feeling for a long time that you are abnormal, you are not alone.
You are in the majority.