A decade ago, at the end of my first semester teaching at Wharton, a student stopped by during office hours. He sat down and burst into tears. My mind started cycling through a list of events that could make a college junior cry: His girlfriend had dumped him; he had been accused of plagiarism. "I just got my first A-minus," he said, his voice shaking.

Year after year, I watch in dismay as students obsess over getting straight As. Some sacrifice their health; a few have even tried to sue their school after falling short. All have joined the cult of perfectionism out of a conviction that top marks are a ticket to elite graduate schools and lucrative job offers.