1. Module 1: Evolution and Economics An Analysis of You: Prisoner’s Dilemma

2. This game is played by two people, designated A and B. This game is played by two people, designated A and B. A plays first and can either cooperate or defect. A plays first and can either cooperate or defect. Knowing A’s choice, B can then either cooperate or defect. Knowing A’s choice, B can then either cooperate or defect.

3. A C D B CD A:$30 B:$30 A:$10 B:$45 A:$15 B:$15 A:$45 B:$10 Player A goes first without knowing what B will do. Player B goes second after learning A’s response.

4. Possible Strategies

5. Unconditional Cooperator: CCC

6. Friendly Tit-for-Tat: CCD

7. Optimistic Non-Cooperator: CDD

8. Pessimistic Tit-for-Tat: DCD

9. Unconditional Non-Cooperator: DDD

10. Wingnuts: CDC, DCC, DDC A DDC Player: “Player A will know I helped them and they might help me in the future.”

11. Your Population? 123T- 4

13. A DCD Player: “I don’t think there are too many people in here who wouldn’t want $45 over $30 if we both decided to cooperate.” TRUST Cooperation by Player A demonstrates trust. Cooperation by Player A demonstrates trust. A CDD Player: “If my partner sees that I chose to cooperate, they may choose to be altruistic and cooperate too so that we both get thirty dollars.”

14. RECIPROCITY Cooperating with a cooperative first mover demonstrates reciprocity. Cooperating with a cooperative first mover demonstrates reciprocity. A CCD Player: “I would cooperate because that’s what I wanted somebody to do, and I’m a nice guy.” A CDD Player: “Because I will make more money this way and the first player can’t stop me.”

15. Self-Sacrifice Cooperating with a non-cooperative first mover demonstrates self-sacrifice. Cooperating with a non-cooperative first mover demonstrates self-sacrifice. A CCC Player: “The effect on me is minimal, but it helps the other person immensely.”

16. The Scientific Method Intro: Ask a question, make a hypothesis. Intro: Ask a question, make a hypothesis. Methods: Do an experiment. Methods: Do an experiment. Results: Analyze outcomes Results: Analyze outcomes Topics for Today: Gender Punishment (& Gender) One Idea From Me A Few From You

17. Statistical Tests

18. Effect Size Effect Size The magnitude of the relationship between variables. The magnitude of the relationship between variables. Specific to a particular test. Specific to a particular test. p-value p-value The probability that an effect size is observed by chance. The probability that an effect size is observed by chance. As the sample size increases, the p-value goes down. As the sample size increases, the p-value goes down.

19. Statistical Tests t-test: t-test: A t-test determines whether the means of two separate groups are equal or not. A t-test determines whether the means of two separate groups are equal or not.

20. Do Males and Females Behave Differently in the Game? Null Hypothesis Null Hypothesis There is no relationship between gender and first mover behavior. There is no relationship between gender and first mover behavior. Alternate Hypothesis Alternate Hypothesis One gender offers cooperation more often than the other. One gender offers cooperation more often than the other.

21. Trust Behavior Between Genders

22. Do Males and Females Behave Differently … In trust behavior? Male Offers = Female Offers? Male Mean =.64 Female Mean =.65 Males = 58 Females = 57 p-value =.901.901 >.05 Insignificant!

23. Reciprocity Between Genders

24. Do Males and Females Behave Differently … In reciprocity? Male Reciprocity = Female Reciprocity? Male Mean =.45 Female Mean =.57 Males = 58 Females = 57 p-value =.120.120 >.05 Insignificant!

25. Punishment: Strategy Differences Without PunishmentWith Punishment

26. Using Variables Independent Variable Independent Variable Something that is controlled for by the researcher. Something that is controlled for by the researcher. Dependent Variable Dependent Variable Something that is observed in terms of the independent variables. Something that is observed in terms of the independent variables. Independent Variable: Punishment Dependent Variables: Trust Reciprocity Altruism

27. What Punishment Does… Trust A CCC Player: “I would cooperate so I wouldn’t get punished.” Played DDD in the first game.

28. What Punishment Does… Trust Offers of Cooperation: w/o Punishment =.64 w/ Punishment =.90 p <.0001 Significant!

29. What Punishment Does… Reciprocity Offers of Cooperation: w/o Punishment =.50 w/ Punishment =.85 p <.0001 Significant!

30. What Punishment Does… Self Sacrifice A CCC Player: “Because if I don’t cooperate, A could punish me.” Played CDD in the first game.

31. What Punishment Does… Self-Sacrifice Offers of Cooperation: w/o Punishment =.09 w/ Punishment =.20 p <.012 Significant!

32. How Do People Punish?

33. Punishment: In-Class Study #2 Selfish Punishers More Males Invest More in Punishment Moralistic Punishers More Females Invest Less in Punishment

34. Punishment Cooperative/ Non- Cooperative Behavior Investment in Punishment Male/Female

35. Selfish vs. Moralistic Punishers: Sex Moralistic Punishers Selfish Punishers Males2418 Females1822 Null Hypothesis: Moralistic & Selfish Punishers are distributed equally between the sexes. Alternate Hypothesis: They are not. p =.272 Do not reject null hypothesis!

36. Punishment Cooperative/ Non- Cooperative Behavior Investment in Punishment Male/Female

37. Selfish vs. Moralistic Punishers Investment in Punishment Null Hypothesis: Moralistic & Selfish Punishers punish equally. Alternate Hypothesis: They do not punish equally. p =.683 Do not reject null hypothesis!

38. Punishment Cooperative/ Non- Cooperative Behavior Investment in Punishment Male/Female

39. Selfish vs. Moralistic Punishers Investment in Punishment Null Hypothesis: Males & Females punish equally. Alternate Hypothesis: They do not punish equally. p <.001 Reject null hypothesis! Males punish more!

40. Punishment Cooperative/ Non- Cooperative Behavior Investment in Punishment Male/Female

41. Social Dependency Predictors of Cooperation: In-Class Study #1 Risk Taking Behavior Trusting People Social Integration

42. First Mover Behavior: Based on Trust? Will People Reciprocate? First Mover Behavior Risk Taking Behavior p =.087 p =.378

43. Risk Behavior QuestionFor SureYour Color Other Color 1Win $2.00Win $10.00 Win $2.00 2Win $3.00Win $10.00 Win $2.00 3Win $4.00Win $10.00 Win $2.00 4Win $5.00Win $10.00 Win $2.00 5Win $6.00Win $10.00 Win $2.00 6Win $7.00Win $10.00 Win $2.00 Score = 6 Most Risky

44. Risk Behavior QuestionFor SureYour Color Other Color 1Win $2.00Win $10.00 Win $2.00 2Win $3.00Win $10.00 Win $2.00 3Win $4.00Win $10.00 Win $2.00 4Win $5.00Win $10.00 Win $2.00 5Win $6.00Win $10.00 Win $2.00 6Win $7.00Win $10.00 Win $2.00 Score = 3 Mildly Risky

45. Risk Behavior QuestionFor SureYour Color Other Color 1Win $2.00Win $10.00 Win $2.00 2Win $3.00Win $10.00 Win $2.00 3Win $4.00Win $10.00 Win $2.00 4Win $5.00Win $10.00 Win $2.00 5Win $6.00Win $10.00 Win $2.00 6Win $7.00Win $10.00 Win $2.00 Score = 1 Least Risky

46. Risk Behavior

47. Risk Behavior and Gender: Discussion Section 1 Null Hypothesis: Moralistic & Selfish Punishers punish equally. Alternate Hypothesis: They do not punish equally. p =.061 Do not reject null hypothesis!

48. Ambiguity Behavior QuestionFor SureYour Color Other Color 1Win $2.00Win $10.00 Win $2.00 2Win $3.00Win $10.00 Win $2.00 3Win $4.00Win $10.00 Win $2.00 4Win $5.00Win $10.00 Win $2.00 5Win $6.00Win $10.00 Win $2.00 6Win $7.00Win $10.00 Win $2.00 Are people… Pessimistic Or Optimistic?

49. Ambiguity Behavior

50. Ambiguity Behavior, Trust and Upbringing? Discussion Section 6 Trust Behavior? Reaction to Ambiguity Rural/Urban p =.901 p =.112

51. Delayed Payoffs QuestionNext WeekOne Day Later 1$35.00$40.00 2$30.00$40.00 3$25.00$40.00 4$20.00$40.00 5$15.00$40.00 6$10.00$40.00 7$5.00$40.00 Score = 0 Most Patient

52. Delayed Payoffs QuestionNext WeekOne Day Later 1$35.00$40.00 2$30.00$40.00 3$25.00$40.00 4$20.00$40.00 5$15.00$40.00 6$10.00$40.00 7$5.00$40.00 Score = 4 Mildly Patient

53. Delayed Payoffs QuestionNext WeekOne Day Later 1$35.00$40.00 2$30.00$40.00 3$25.00$40.00 4$20.00$40.00 5$15.00$40.00 6$10.00$40.00 7$5.00$40.00 Score = 7 Least Patient

54. Delayed Payoffs

55. Delayed Payoffs and Urban/Rural: Discussion Section 3 Null Hypothesis: Desire for immediate pay is unrelated to urban/rural upbringing. Alternate Hypothesis: People from different upbringings fel differently about delayed payoffs. p =.159 Do not reject null hypothesis!

56. A Biological Perspective

57. Dopamine System Bilateral Insula Brain Center Reward circuitry Disgust, Pain, Hunger Job During mutual cooperation During low offers in U.G. Stimulated during Games? Strength correlates with cooperation and punishment. Increases Punishment Operation during Games?

58. An Evolutionary Perspective Need for Cooperation in Evolutionary Past Neurology which Supports Cooperation Cooperative Behavior “Does my Environment Need Cooperation?”