Lessons from the Student’s Dilemma, the extra credit version of the Prisoner’s

Dylan Selterman, a psychology lecturer at the University of Maryland, presents the above problem—a variation of the Prisoner’s Dilemma—as extra credit on his exams. He’s done this since 2008, but a student recently posted a picture of the question and it spread through the networks of social media.

The question amuses, but naturally, it evokes another: How do students answer? For Quartz, Selterman describes the results and the overarching moral lessons we can learn from them.

It’s important to note that most students in my class (around 80% each semester) end up choosing two points. While many students choose the “rational” six-point option, they are still in the minority.

I believe this is because most people do understand the importance of being communal. In other words, most people are happy to behave in a way that benefits others around them.

The problem is that there is still many who don’t. With the exception of one year, no class received extra points, because more than 10 percent of students selected the greater six-point option.