Friendship is the hardest thing in the world to explain. It's not something you learn in school. But if you haven't learned the meaning of friendship, you really haven't learned anything.
Muhammed Ali
After
having played the game, the players were taken away from the videoconference
(so they could not negotiate their answers) and given a sheet with the following
text:
You have a chance to increase your payment for this experiment.
Here is the deal: You have the choice to draw a big X on
the back of this sheet. If there is an X on your sheet, and NOT the other
person's sheet, you get another €10. Of course, if the other player
has an X, and you don't, she/he gets the €10. If each of you put nothing
on your sheets, each of you gets another €5. BUT if there is an X on
your sheet AND on the other player's sheet, you will both receive nothing
extra.
This test was chosen to examine how much the players would cooperate in both conditions after having played the game. It is a variation of the often used 'Prisoner's Dilemma'.