Christopher X J. Jensen
Associate Professor, Pratt Institute

Easy Iterated Prisoner’s Dilemma

Easy Iterated Prisoner’s Dilemma (Easy-IPD) allows novice users to explore the rich and complex dynamics of Robert Axelrod‘s iterated prisoner’s dilemma tournaments using a simple, user-friendly interface. Because it is Flash-based, Easy IPD can be embedded into websites in a variety of ways and requires no special installation (although you should have the latest version of Adobe Flash Player installed).

I teach about the iterated prisoner’s dilemma (IPD) in my Evolution of Cooperation and Human Evolution courses, but have always struggled with how to give students a meaningful understanding of this model’s significance. To really understand how the IPD works, you need to have the ability to play around with different tournaments: to pit different strategies against each other, see which strategy emerges victorious, and then dissect the results to understand why a particular strategy was most successful. This is what Axelrod did in his famous tournaments (reported in his book The Evolution of Cooperation), and it is easy enough to just rattle off his important conclusions to students. But to have those same students re-discover Axelrod’s results based on their own inquiries is to build true understanding, and it is this inquiry-based discovery that Easy-IPD empowers.

Here is the Easy-IPD interface:

If you would like to open Easy-IPD in its own window (which allows you to re-size the interface), navigate here. If you would like to embed Easy-IPD into your course management system or your own site, you can download the source file here.

I plan to develop curricular materials to accompany the Easy-IPD interface. Please check back here soon for an instructor’s guide and student worksheets.

I developed this interface in collaboration with Jean Ho Chu, who did all of the design work and programming in Flash. We invite your comments and suggestions. Also, let us know if you are using this tool in your classroom!

You can see all my posts related to this project here.

Teachers who are using Easy Iterated Prisoner’s Dilemma in the classroom:

Are you using Easy Iterated Prisoner’s Dilemma in your classroom? If so, let me know!

Jean Ho Chu’s work on this project was supported by a Pratt Institute Graduate Research Assistant stipend.