Why we should stop grading students on a curve


Foster collaboration in exams, not cut-throat competition

Ask people what's wrong in American higher education, and you'll hear about grade inflation. At Harvard a few years ago, a professor complained that the most common grade was an A-. He was quickly corrected: The most common grade at Harvard was an A.

Across 200 colleges and universities, more than 40 per cent of grades were in the A realm. At both four-year and two-year schools, more students receive As than any other grade - a percentage that has grown over the past three decades.

Among older graduates, figures like these usually elicit a comment involving the words "coddled", "damn" and "millennials". But the opposite problem worries me even more: grade deflation. It happens whenever teachers use a forced grading curve: The top 10 per cent of students receive As, the next 30 per cent get Bs, and so on. Sometimes it's mandated by institutions; sometimes it's chosen by teachers.

The goal is to fight grade inflation, but the forced curve suffers from two serious flaws. One: It arbitrarily limits the number of students who can excel. If your forced curve allows for only seven As, but 10 students have mastered the material, three of them will be unfairly punished. (I've found a huge variation in overall performance among the classes I teach.) After analysing grading systems, economists Pradeep Dubey and John Geanakoplos concluded that a forced grade curve is a disincentive to study. "Absolute grading is better than grading on a curve," they wrote.

The more important argument against grade curves is that they create an atmosphere that is toxic by pitting students against one another. At best, it creates a hypercompetitive culture, and at worst, it sends students the message that the world is a zero-sum game: Your success means my failure.

A few years into my teaching career, I set out to change that attitude among my students.

When students take the time to find out who has expertise, they become smarter at learning. And that is ultimately what we are trying to teach, isn't it? The mark of higher education is not the knowledge you accumulate in your head. It is the skills you gain about how to learn.

I started experimenting with grading schemes that would encourage community and collaboration - while still maintaining standards and assessing students individually.

In fairness, many people believe in the opposite view - that the world is a zero-sum game - and that colleges (especially business schools like the one where I teach) should reflect that reality. I understand their view, but as an organisational psychologist, I've found that they are wrong.

Exhibit A: The time employees spend helping others contributes as much to their performance evaluations and promotion rates as how well they do their jobs. That's the punchline of a comprehensive analysis of 168 studies of more than 51,000 employees across industries: Leaders reward people who make the team and the organisation more successful.

Exhibit B: I spent a decade studying the careers of "takers", who aim to come out ahead, and "givers", who enjoy helping others. In the short run, across jobs in engineering, medicine and sales, the takers were more successful. But as months turned into years, the givers consistently achieved better results.

Takers believe in a zero-sum world, and they end up creating one where bosses, colleagues and clients don't trust them. Givers build deeper and broader relationships - people are rooting for them instead of gunning for them.

Like most people in business schools, my students were intent on networking, but they focused their efforts outside their classes and regarded their in-class peers as competition. I decided to change that culture seven years ago, knowing it would be difficult. There's evidence that once a competitive culture emerges in a group, it's difficult to undo - people fall into a pattern of "cutthroat cooperation". I began my experiment by writing unusually difficult exams. That was enough to motivate students to study hard. And I introduced a rule: No student will ever be hurt by another student's grade. After several voiced worries that they would all be hurt, I promised them that I would never curve downward, only upward. If the highest mark was an 83, I would add 17 points to everyone's score. Now one student's excellence didn't hurt another's grade.

But while that removed a level of competition, it did not address the bigger goal, which was to make preparing for my exam a team effort. How could I get students to help one another?

Four years ago, I found a way. The most difficult section of my final exam was multiple choice. I told the students that they could pick the one question about which they were most unsure, and write down the name of a classmate who might know the answer - the equivalent of a lifeline on the game show Who Wants to Be a Millionaire? If the classmate got it right, they would both earn the points.

Essentially, I was trying to build a collaborative culture with a reward system where one person's success benefited someone else. It was a small offering - two points on a 120-point exam - but it made a big difference. More students started studying together in small groups, then the groups started pooling their knowledge.

The results: Their average scores were 2 per cent higher than the previous year's, and not because of the bonus points. We've long known that one of the best ways to learn something is to teach it. In fact, evidence suggests that this is one of the reasons firstborns tend to slightly outperform younger siblings on grades and intelligence tests: Firstborns benefit from educating their younger siblings.

Psychologists Robert Zajonc and Patricia Mullally noted in a review of the evidence that "the teacher gains more than the learner in the process of teaching".

I had been trying to teach this lesson through my research on givers and takers, but it was so much more powerful for them to live it.

Creating an atmosphere in which students want to help one another also allowed them to benefit from another of the defining features of personal and professional relationships: transactive memory, which is simply knowing who knows best.

In a marriage, you don't need to know how to fix the air-conditioner if your wife does. In a work team, you don't have to know how to perfect PowerPoint slides if your colleague is an expert.

Even in the world of finance, where success is supposed to be about raw brain power, research shows that star investment analysts who join new firms see their performance drop for the next two years - unless they take their teams with them. It takes time to learn who knows what. Transactive memory makes it easier to ask for help - you know where to turn.

When students take the time to find out who has expertise, they become smarter at learning. And that is ultimately what we are trying to teach, isn't it? The mark of higher education is not the knowledge you accumulate in your head. It is the skills you gain about how to learn.

By 2014, before the final exam, a student sent an e-mail to the entire class announcing that she and a friend had reserved a room for Saturday afternoon studying, and anyone was welcome to join them. That night, another student suggested that the class could divide up the readings and write summaries. Two minutes later, a third student responded: He had already taken the initiative to write a comprehensive study guide, which he shared with the entire class. Many students contributed their own insights, and one even made a practice quiz - a smart idea since it is well established that testing is a better way to learn than regular studying.

That year, the scores climbed another 2.4 per cent. "Your class has changed the way students work together," one student wrote to me. "I've never seen a group of students so willing to help one another succeed."

Her note suggested that there was another powerful reason to abandon grading on a curve. One of the most robust predictors of stress, depression and burnout is a lack of "belongingness" and social support. And we know that when disadvantaged students are motivated to seek help, their grades improve.

Colleges today are trying to deal with a substantial suicide risk among students and growing rates of depression and anxiety. On my most optimistic days, I wonder whether campus mental health would improve if more classes were designed to encourage participants to support one another. Would students be better off if they saw classmates as people who had their back, rather than as people who might stab them in the back?


• The writer is a professor at the Wharton School of the University of Pennsylvania, and the author of Originals and Give and Take.

A version of this article appeared in the print edition of The Sunday Times on September 18, 2016, with the headline 'Why we should stop grading students on a curve'. Print Edition | Subscribe