How to Solve the Prisoner’s Dilemma: A Gloriously Animated Explanation of the Classic Game-Theory Problem

Imag­ine two pris­on­ers, each one placed in soli­tary con­fine­ment. The police offer a deal: if each betrays the oth­er, they’ll both get five years in prison. If one betrays the oth­er but the oth­er keeps qui­et, the betray­er will walk free and the betrayed will serve ten years. If nei­ther say any­thing, they’ll both be locked up, but only for two years. Unable coor­di­nate, both pris­on­ers will like­ly betray each oth­er in order to secure the best indi­vid­ual out­come, despite the fact that it would be bet­ter on the whole for both to keep their mouths shut. This is the “pris­on­er’s dilem­ma,” a thought exper­i­ment much-cit­ed in game the­o­ry and eco­nom­ics since the mid­dle of the twen­ti­eth cen­tu­ry.

Though the sit­u­a­tion the pris­on­er’s dilem­ma describes may sound quite spe­cif­ic, its gen­er­al form actu­al­ly con­forms to that of a vari­ety of prob­lems that arise through­out the mod­ern world, in pol­i­tics, trade, inter­per­son­al rela­tions, and a great many oth­ers besides.

Blog­ger Scott Alexan­der describes the pris­on­er’s dilem­mas as one man­i­fes­ta­tion of what Allen Gins­berg called Moloch, the relent­less unseen force that dri­ves soci­eties toward mis­ery. Moloch “always and every­where offers the same deal: throw what you love most into the flames, and I can grant you pow­er.” Or, as he’d put it to Chewy the gin­ger­bread man, “Betray your friend Crispy, and I’ll make a fox eat only three of your limbs.”

Such is the sit­u­a­tion ani­mat­ed in glo­ri­ous­ly wool­ly stop-motion by Ivana Bošn­jak and Thomas John­son in the TED-Ed video at the top of the post, which replaces the pris­on­ers with “sen­tient baked goods,” the jail­er with a hun­gry wood­land preda­tor, and years of impris­on­ment with bit­ten-off arms and legs. After explain­ing the pris­on­er’s dilem­ma in a whim­si­cal man­ner, it presents one pro­posed solu­tion: the “infi­nite pris­on­er’s dilem­ma,” in which the par­tic­i­pants decide not just once but over and over again. Such a set­up would allow them to “use their future deci­sions as bar­gain­ing chips for the present one,” and even­tu­al­ly (depend­ing upon how heav­i­ly they val­ue future out­comes in the present) to set­tle upon repeat­ing the out­come that would let both of them walk free — as free as they can walk on one gin­ger­bread leg, at any rate.

via Aeon

Relat­ed con­tent:

An Intro­duc­tion to Game The­o­ry & Strate­gic Think­ing: A Free Course from Yale Uni­ver­si­ty

An Ani­mat­ed Intro­duc­tion to the Famous Thought Exper­i­ment, the “Trol­ley Prob­lem,” Nar­rat­ed by Har­ry Shear­er

The Famous Schrödinger’s Cat Thought Exper­i­ment Comes Back to Life in an Off-Kil­ter Ani­ma­tion

Watch a 2‑Year-Old Solve Philosophy’s Famous Eth­i­cal “Trol­ley Prob­lem” (It Doesn’t End Well)

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities, the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or on Face­book.