David's Sling by Marc Stiegler Page A

of the Prisoner's Dilemma apply to many real-life situations. We ll discuss some of the applications after we've analyzed the results of the game. The game might seem silly now, but remember that even obvious ideas need to be exercised before you can truly own them. You can't get more out of this seminar than you're willing to put in."
    "But I can get a lot less than I put in."
    "True enough. Life is generally like that—you must put something in to get something out."
    Bill growls, "Okay."
    "Good. You'll play this game with ten randomly selected people from the class. Then you'll play with them all again. We'll play ten rounds with each player and then discuss the results. For every game, all you have to do is punch either the Conspire button or the Betray button." Hammond shoots him a quizzical look. "So how are you going to play?"
    Bill thinks about it for a long moment. "The only rational thing to do is to betray the other guy," he states with confidence. "You just can't take a chance on some random human being."
    "I see your point." Hammond's smile again makes him feel like a bug under a microscope. "We'll keep score by adding up the years in jail you accumulate. Good luck. The door swished softly behind him.
    Bill looks at the terminal, annoyed by this pointless game that dooms all the players to lose. Surely, everyone here is as rational as he is; if so, there will be an endless series of betrayals.
    The terminal comes to life, telling him he is matched with partner number one, and that they have never played together before. Bill stabs the Betray button.
    In less than a minute Bill realizes that not everyone is rational. Several people offer to Conspire in that first round, and they take terrible punishments as Bill betrays them. Bill himself gets off lightly. In the second round, he finds that the terminal gives him a description of his history with his opponent. He stabs the Betray button with a moment's regret—and realizes that when he thinks of the other player as an opponent , he is creating a fundamental statement about his relationship.
    Seeing himself paired with a player who had given him a valuable Conspiracy the last time, Bill generously offers a Conspiracy in return—but the bastard Betrays, leaving Bill holding the bag. After a few more plays, Bill realizes that these people don't trust him worth a damn. He admits—with considerable reluctance—that he has given them cause for suspicion. In self-defense, he reverts to a constant stream of Betrayals.
    On the third round, the handful of people to whom he has offered Conspiracies in the second round come back with Conspiracies for him. Of course, he has given up any acts of mercy, zapping all players with Betrayals.
    Meanwhile, two of the players have doggedly continued to give him Conspiracies. It matters not that he Betrays them again and again. On the fourth round he reciprocates, and they remain as solid partners till the last round of the game. He gives up on the ones with whom he seesaws back and forth from Betrayals to Conspiracies, and switches to permanent Betrayals. They do the same.
    At the end of ten rounds, he has accumulated over a century in jail.
    Hammond pokes his head in. "How'd you do?" he asks.
    FOCUS. Bill shrugs. "As well as anybody, I guess."
    Back in the discussion room, Hammond disproves that assessment. Several people do substantially better than Bill. Hammond points out key features of the "winners."
    The winners had three distinctive characteristics: They were optimistic , offering to Conspire with untested partners. They were just, never letting a Betrayal go without response. And they were predictable in their responses , so their partners knew what they would do at all times. With sudden insight, Bill realizes that these people were the ones with whom he had seesawed early in the game; his stubborn Betrayals constituted a major part of their losses. Of course he had shared their losses, since they soon responded with