Peter Huynh, a 19-year-old college freshman, panicked when he learned the details of an unusual class assignment. As part of a lesson in “social courage,” his professor instructed her students to ask someone of “legitimate romantic interest” out on a date. “I retched,” says Mr. Huynh, who attends Boston College.

He drew up a list of 10 fellow freshmen, with pros and cons for why he should ask each one out. He solicited advice from a teaching assistant. Then he decided on a cute girl in one of his classes whom he hardly knew....