Monday, April 22, 2013

The Fallacy of the Bell Curve: Shooting for Mediocrity

Most of us are familiar with the idea of a bell curve.  If you grew up with public education in the US in the 1970s, you were likely steeped in it.  The idea is fairly simple:

"First, numeric scores are assigned to the students. The actual values are unimportant as long as the ordering of the scores corresponds to the ordering of how good the students are. In the second step these scores are converted to percentiles. Finally, the percentile values are transformed to grades according to a division of the percentile scale into intervals, where the interval width of each grade indicates the desired relative frequency for that grade.

For example, if there are three grades, A, B and C, where A is reserved for the top 10% of students, B for the next 20%, and C for the remaining 70%, then scores in the percentile interval from 0% to 70% get grade C, scores from 71% to 90% get grade B, and scores from 91% to 100% get grade A."
Okay, that's how we got our 'letter grades.' What I find particularly interesting about this method is the following statement - also from Wikipedia.

"The grading method can thus be tuned to determine the frequency distribution of the grades in advance, and if the intervals are already fixed at the beginning of a course, then so is the number of students who will receive each grade."

Regardless of how you feel about the format of "grading on a curve," it occurs to me that as a culture, we have bought into this notion and applied it to nearly everything.  We use the idea that most of us are going to be clustered into the center portion of the curve, sheltered under its wide arc, with only the outliers spread out to either side, to make sense of our world. We live our lives aspiring to be, if not to the far right side of that graph, at least safe within the numbers of other 'normal' folks like us in the main part.

And it's no wonder, because those unlucky folks at either end of the spectrum are often the ones who are dehumanized.

Consider a bell curve based on sporting ability.  The folks at the far right - the positive 2.5s and 3s - those are Michael Phelps, Lance Armstrong, Mia Hamm. They are the ones we revere and admire and pay bucketloads of money to go see in action, but they are also relegated to that world of superhuman ability that makes them subject to expectations nobody can meet.  We idolize them and dehumanize them. We ask that they subjugate their humanity, their tendency to make mistakes and their desires for junk food and bad relationships, in order to explain to ourselves why they aren't in the same part of the bell curve as us.  And if they fall for any reason at all and show their flaws and foibles, we vilify them viciously before either ignoring them or dusting them off and placing them right back on that pedestal where we want them to be.

We have graphs for every kind of achievement and quality - musical talent, scientific thought, physical attributes - and we hold exacting standards for each of them. Talented musicians are prodigies whose lives are wasted if they deign to seek anything other than a life of fame and fortune by making music. Gorgeous models and actors are lauded for maintaining their ideal weight and if one should suffer some disfiguring accident we assume their life is now over.

And if we all adhered to our places on the bell curve, where might we be?  There would be no Temple Grandin, for she would be relegated to the negative twos with other folks whose talents don't fit in with our idea of 'normal.' The work of Martin Luther King, Jr. and Rosa Parks would never have materialized, given their place on the bell curve of gender and race.  It is so often those individuals who are willing to step outside of the interval that society has fixed in place for them who make the biggest impact, who believe that we have something important to learn, but they suffer greatly at the hands of those who would define them as less human simply because of that place they are supposed to occupy on the graph.  We are, so many of us, concerned with having what is average, what is normal, with sitting firmly in the middle of an entire group of others just like us, that we forget to dream. We accept the idea that the game is fixed, the intervals are set, and we have little mobility to the right or to the left. We know, from working out the statistics of the bell curve, that once you reach a certain point, it is simply too hard to break through to the top part of the curve.

It hasn't always been this way. Our country used to be one that fairly demanded difference. There was a time when our shores were flooded with immigrants that were welcomed and, although they didn't always have what they needed to get by, collaboration and innovation were praised, not to mention a survival necessity. That's not to say that there aren't shameful examples of exploitation and discrimination in our history, but there wasn't always this idea that being just like everyone else was something to aspire to.  In the 1950s when television programs began showing us what we should want, we stopped asking ourselves what we actually did want and found it was simpler to go along with the crowd. Unfortunately, that has turned into a self-fulfilling prophecy for many Americans who would rather blend into the sheer numbers of others like themselves than celebrate their own unique attributes and talents. It has also made it much easier to dehumanize individuals at both ends of the spectrum, pitying those on one end of the curve and holding those at the opposite end to an impossible standard. We huddle in our "normalcy," afraid to bust out at either side and show our true desires and talents, content to paint ourselves in the colors of the masses and regard those remarkable individuals who stand out like exotic creatures at the zoo.  A dynamic, diverse society is one that allows for difference and celebrates every kind of unique thought, not one that is frightened of new frontiers and innovation. Let's scrap this bell curve and start looking at our world through fresh eyes.


Carrie Link said...

Amen. said...

My kids are both taking standardized tests this week.
We've emphasized to them both that it doesn't mean much in the grand scheme of their lives, and hope they don't sweat it.

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