Lab 2 - Prisoner's Dilemma

Goals

1. To show how evolutionary stable strategies work in nature.
2. To demonstrate how reciprocity and altruism might evolve naturally.

Prisoner's Dilemma Overview

In this activity you will form groups of three. Two individuals will play the game and one individual will serve as the observer, recording the game play.

Players:

1. The players will face each other, with a "goalspot" in front of them. A penny will be placed in the center of the gameboard.
2. Players should attempt to maximize their winnings and minimize their losses. The players will play the game 10 times, taking turns at going first.
3. In each game, each player has only 10 moves to try to move the penny into his or her own goalspot, for a total of 20 moves per game.
4. The penny can be moved only one circle at a time and only by following the lines connecting two circles.
5. If after 20 moves neither player has moved the penny into their own goalspot, the game ends in draw and neither player wins.
6. The observer will count the number of moves made in the game, so don't move too quickly!
7. The game must be played in TOTAL SILENCE.The players should not talk or otherwise signal each other before, during, or between all 10 games. You may discuss the game freely once all 10 games have been completed.
8. Toss the penny and have one player call heads or tails to determine who will start the first game.

Observers:

1. You will use your data sheet to record the moves for each game. It is important that you accurately record all the move locations and which move of the game it was. See the sample data sheet for an example.
2. Once all 10 games are completed, you will analyze the data along with the other members of your group.

Data Summary Sheet

From the following options, determine the strategy for each of the 10 games. You may not see many instances of "pure" competition or cooperation. However, if the majority of the moves indicate cooperation, competition, or conflict avoidance, choose that option.

Data Summary Sheet(/1)
Names:
	Game Outcome	Type of Strategy
Game #	Player A Won	Player B Won	Draw	Competition	Cooperation	Conflict Avoidance	Mixed Strategy
1
2
3
4
5
6
7
8
9
10
Average # of wins per player:
Calculating averages: (total # of times Player A won + total # of times Player B won) /2

Data Interpretation

1. In your group what strategy was most common? How did this compare to other groups? a.

2. In this version of the prisoner's dilemma game there are multiple opportunities to win or lose. How do you think strategies might change if the players only played a single game?

a.

3. How did Player A's behavior influence what Player B chose to do (or vice versa)? Provide at least two specific ways.

a.

4. What do these data tell us about humans and their decisions on when to cooperate with one another?

a.