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Student grades have been rising steadily at many universities over the past few decades, according to a new report that tracks GPAs at more than 200 American schools. This grade inflation is a problem because it dilutes the meaning of grades as a measure of performance. If most students finish college with an 'A' average, potential employers and graduate schools have a tougher time distinguishing the most competent and hard-working of their applicants.
The causes of grade inflation have been debated for years, serving up a mishmash of explanations. However, far from clarifying its causes, this debate is often used as a platform to blame grade inflation on whatever the explainer thinks is wrong with universities, or society, in general. To give you a taste, grade inflation has been blamed on the way states fund their public universities, the way student evaluations affect faculty promotions, the increasing use of part-time instructors, too much compassion from instructors, student entitlement, a growing consumer culture, the Vietnam War, and greater diversity on college campuses. While we're at it, why not blame global warming and the fall of the Soviet empire too?
One detail that's rarely mentioned about grade inflation, though, is that it has not been happening everywhere. In fact, the most surprising thing is that grades tend to be high at prestigious (1st-tier) universities and lower at less prestigious (2nd-tier) schools. This difference is evident for both public and private schools. For example, Harvard, Yale, Berkeley, and U. of Virginia have GPAs averaging around 3.4 (out of 4.0), while schools like Norfolk State, South Carolina State, and U. of Houston average around 2.6.
This difference floored me when I first learned of it—intuitively, I'd expect prestigious schools to have tougher standards and if anything, lower grades.
Any explanation for grade inflation needs to account for why it's strong at prestigious schools but weak or absent at 2nd-tier schools, and I have yet to hear one that's convincing. So to join the throng of theories, I'll add my own: Grades are higher at prestigious schools because instructors there use different standards than instructors at less prestigious schools.
This is what I mean: Instructors don't just assign grades based on how students in their class compare to one another, they also base their grades on how each student compares to other students at other universities. This second comparison causes grades to be awarded differently at prestigious vs. non-prestigious schools.
Consider a Harvard student, Bob, who performs worse than most of his classmates on his English composition final. Even though his instructor will evaluate Bob relative to his other classmates (let's call this a local comparison, within the class) to some extent, the instructor's evaluation will also be affected by a more global comparison of Bob to all other college students in the world. This global comparison will work in Bob's favor, since Harvard students compare well to college students in general. This favorable evaluation could factor into Bob's grade, even if the instructor's intention is to base the grades only on the local comparison between classmates.
This happens because of a more general bias people have whenever we judge how one member of a group compares with the other members of that group. Even when trying to make a purely local (within-group) comparison, like Bob to his classmates, it's hard to disregard Bob's overall strength as a student, and this appraisal inadvertently rubs off on our local judgment. Here's a more blatant example of this happening:
Imagine you just got done interviewing 5 outstanding candidates to be the new CFO of your company. All the candidates were equally qualified for the job and you know you'll have a tough time deciding who to hire. Now let's say you happen to start thinking about Candidate #5, since that interview is still fresh in your mind. You consider how Candidate #5 compares to the other four candidates: Is #5 above average within the group, below average, or just average? Although this is a local comparison, your positive feelings toward #5—because he's more competent and charismatic than most of the people you've ever met—will unconsciously factor into your judgment and lead you to perceive #5 as above average vs. the group. Ideally, if your goal is to choose the best of these five applicants, you wouldn't want your judgment to be affected by any global standard, since it's irrelevant to the decision and might prevent you from using a better selection strategy. (Note: Whichever candidate you happened to compare to the group would also be perceived as above average, defying a rational analysis.)
This bias can operate in the negative direction as well. For example, if you were to judge how unpleasant one of your enemies was, relative to all your enemies, you'd probably rate this particular enemy as more unpleasant than the others. Similarly, at a low-status university, where students don't compare well to the other college students in the country, this global comparison could cause each student to be viewed as below average within their school, keeping the average GPA there low.
And it's not just instructors who would fall prey to this local/global bias; it could also affect the way students evaluate themselves and the grades they deserve. The average Harvard student might feel they deserve higher grades than their classmates, while the average student at Norfolk State might perceive themselves as below average relative to their classmates. These expectations would influence how they react to the grades they get, and at schools where expectations are high, this could lead to subtle pressure for instructors to award higher grades.
None of this implies that local comparisons should be the only basis instructors use when assigning grades; global standards and personal standards are also important factors. But global standards affect our judgments more than we realize, and this may explain why grades are higher at prestigious schools. This analysis also suggests that the higher grades won't be reversing themselves anytime soon.
More generally, this local/global bias is sure to bear upon other decisions where we evaluate one thing against the others in its group—whether one home is better than other prospective homes on the market, how one candidate running in your party's primary elections compares to the other candidates, or even deciding which type of candy or which type of pesticide to buy at the store. When choosing from a group of good things, each one will seem better than the last; when choosing from a group of bad things, each will seem worse.
