This particular argument is, I think, weaker than many of the other ideas Alfie Kohn promotes in his books, two of which I have read and admired. However, I have seen what happens when the competition and stress of grades is removed.
We had one teacher, in math actually, who told the class they all had A’s before the class started. He also encouraged team test-taking and peer help and collaboration in general. The kids loved it and learned by teaching others, since competition was removed. Parents complained!!!
I also know of a college TA who assigned ungraded writing assignments. The students produced unbelievable writing without the stress of worrying about grades. They were more creative, taking more risks. And they had fun.
It is not hard to understand why some “progressive” colleges have historically not graded work but instead offered narrative evaluations, which are not competitive, do not sort, but address each individual. Clearly large high schools cannot do this, but it would be ideal.
In some of his books, Kohn reminds us that grades are not a goal in and of themselves: they are a measure of learning. In my experience, most teachers have forgotten this. When my kids brought report cards home, I did not look at them unless there was a reason to. I knew who was working hard and that was what mattered. I credit Kohn with this.
Kohn also makes interesting distinctions between external motivators (grades, college admissions are examples) and internal motivators. In psychology, the move to internal from external is a sign of transition to maturity, but grading systems (and college admissions competition) actually keep people in a less mature way of functioning.
Finally, in many ways, grading is not fair. The kids who work hardest don’t always get the best grades. Perhaps there is a way to include effort in grading.
I know my comments aren’t relevant here except to say that the real goal would be for people, both those who give then and those who get them, to understand what grades really are. As a measure of learning, and perhaps most importantly a measure of hard work, the inevitable sorting that results would at least be fair.
Or we could find a way to get rid of grades entirely.