1. Team Games: Intra- and Intergroup Conflict Robert Böhm + Ori Weisel § + RWTH Aachen University § University of Nottingham IMPRS Uncertainty Summer School Jena 2015

2. Main results so far Intergroup Prisoner’s Dilemma (IPD; Bonrstein and Ben-Yossef 1994) Ingroup love and outgroup hate are confounded Intergroup Prisoner’s Dilemma – Maximizing Difference game (IPD-MD, Halevy, Bornstein, and Sagiv 2008) Ingroup love is the main motivation Ontogeny of ingroup love and outgroup hate (Buttelman and Böhm 2014) Ingroup love develops earlier Ori Weisel University of Nottingham

3. The Biological Basis of Parochial Altruism (De Dreu et. al. 2010) Parochial Altruism: The willingness to incur a personal cost to in order to favor the ingroup over the outgroup. Can be motivated by ingroup love and/or outgroup hate. How/when did it evolve? “Groups with a greater number of courageous, sympathetic, faithful members, who were always ready to warn each other of danger, to aid and defend each other…would spread and be victorious over other tribes” (Darwin, 1873) Implication: The human brain evolved to facilitate contributions to in-group welfare, and to defend against outside threats, including competing groups.

4. The Biological Basis of Parochial Altruism (De Dreu et. al. 2010) Research question: does parochial altruism have its biological basis in oxytocin? Why Oxytocin? The “love hormone”; known for its role in pair-bonding, sexual activity, child birth, lactation and maternal bonding. Recently found to have additional social functions: related to recognition of emotions and faces (Domes et al. 2007; Guastella et al. 2008, 2010) Increases offers in ultimatum game, not in dictator game (Zak, Stanton, Ahmadi, 2007) Increases offers in dictator game (Knafo et al. 2008, Israel et al. 2009) Increases trust (Kosfeld et. al, 2007)

5. Trust game (Kosfeld et al. 2007) Both the investor and the trustee receive a 12 MU endowment. Investor can transfer 0, 4, 8, or 12 to the trustee. The transfer is multiplied by 3. Trustee can send any amount back to investor. Oxytocin Placebo

6. Experiment 1: Intranasal oxytocin/placebo administration Double blind design 30-40 minutes later: IPD-MD IPD-MD: two 3-person groups Each person has a €10 endowment Decides how much to contribute to within- and/or between group pool Each €1 contributed to the within-group pool: +1 to each group member Each €1 contributed to the between-group pool: + €1 to each group member, - €1 to each outgroup member Two conditions: Placebo vs. Oxytocin The Biological Basis of Parochial Altruism (De Dreu et. al. 2010)

7. Oxytocin increases ingroup love, not outgroup hate Additional analysis: Egoists -> give more to themselves than to ingroup love or outgroup hate Ingroup lovers -> give more to ingroup love than to outgroup hate or to themselves Outgroup haters -> give more to outgroup hate than to ingroup love or to themselves EgoistsIngroup lovers Outgroup haters Placebo52%20%28% Oxytocin17%58%25%

8. The Biological Basis of Parochial Altruism (De Dreu et. al. 2010) Experiment 2: Same as Experiment 1, with classification of participants to cooperative (pro- social) vs. non-cooperative (individualistic-competitive). Oxytocin increased ingroup love for both cooperative and non-cooperative people.

9. The Biological Basis of Parochial Altruism (De Dreu et. al. 2010) Experiment 3: Decisions in PD games, on behalf of the ingroup (vs. outgroup). Non-cooperation can be a result of greed (exploit the outgroup) or fear (protect the ingroup). Greed = T - R Fear = P - S Greed = 0.40 Fear = 0.40 Greed = 0.10 Fear = 0.10 Greed = 0.10 Fear = 0.40 Greed = 0.40 Fear = 0.10

10. The Biological Basis of Parochial Altruism (De Dreu et. al. 2010) Oxytocin increased non-cooperation only when fear was high. General conclusions: “Specific forms of parochial altruism have their biological roots in oxytocin. Oxytocin leads to more ingroup love (and ingroup trust), and defensive forms of out-group hate.”

11. Additional (negative) effects of oxytocin Promotes ethnocentrism (De Dreu et al. 2010) Implicit association test infrahumanization task Promotes groups serving dishonesty (Shalvi and De Dreu 2014) Coin flipping task

12. Ingroup love vs. universal love (Israel, Weisel, Bornstein, Ebstein 2012) In a competitive intergroup context oxytocin leads to concentration on the ingroup. What is the effect of oxytocin in a cooperative intergroup context? Nested social dilemma (Wit and Kerr 2002) Choice between personal pool (keeping), local (in-group) pool, or global (collective pool). Does oxytocin effect contributions to local and/or global pools?

13. Ingroup love vs. universal love (Israel, Weisel, Bornstein, Ebstein 2012) Personal pool 6 MU to self 0 MU to each in-group member 0 MU to each out-group member Local pool 3 MU to self 3 MU to each in-group member 0 MU to each out-group member Global pool 1 MU to self 1 MU to each in-group member 1 MU to each out-group member

14. Ingroup love vs. universal love (Israel, Weisel, Bornstein, Ebstein 2012) N=96, Males only, 18-35 years old No past or present psychiatric or medical illness No present use of medications or drugs No history of drug or alcohol addiction All experiments took place at the same hour (2:30 pm) No smoking, eating, drinking (except water) 2 hours before the experiment Double-blind design: Hormone puffers differentiated only by random number; puffers contain exactly the same ingredients, (save the active ingredient) - no difference in taste, smell, or ph level between hormones and placebo ~45 minute lag between hormones administration and the decision to allow for the hormones to exert their full effects Average earning per participant about €25

15. Ingroup love vs. universal love (Israel, Weisel, Bornstein, Ebstein 2012) Oxytocin increased contribution to both the local and global pools. Conclusion: the selective effect of oxytocin on the ingroup contributions is limited to competitive intergroup contexts. In cooperative intergroup context oxytocin has an affect on contributions to the outgroup(s) as well.

16. Intergroup conflict in a repeated game (Halevy, Weisel, Bornstein 2012) Intergroup conflict typically involves numerous interactions A repeated IPD-MD game may escalate into a full scale “war” Three intergroup histories (conditions): 72 3-person groups (24 in each condition) Endowment = 2 MU. Contribution:+1 MU to each ingroup member -1 MU to each outgroup member in IPD and between group pool in IPD-MD Rounds 1-30Rounds 31-60 Repeated IPD-MD IPD-MD Conflict IPDIPD-MD Peaceful coexistence PDIPD-MD

17. Intergroup conflict in a repeated game (Halevy, Weisel, Bornstein 2012) Even in repeated setting, very little outgroup hate in IPD-MD Even after ‘history of conflict’, when the option to cooperate internally was introduced, almost all participants changed their strategy almost immediately. Without any verbal communication, and with very little signaling (within 2 rounds)

18. Main results so far Intergroup Prisoner’s Dilemma (IPD; Bonrstein and Ben-Yossef 1994) Ingroup love and outgroup hate are confounded Intergroup Prisoner’s Dilemma – Maximizing Difference game (IPD-MD; Halevy, Bornstein, and Sagiv 2008) Ingroup love is the main motivation Ontogeny of ingroup love and outgroup hate (Buttelman and Böhm 2014) Ingroup love develops earlier Biological basis of parochial altruism (De Dreu et al. 2015) Oxytocin related to ingroup love, not outgroup hate Repeated IPD-MD, history of conflict (Halevy, Weisel, and Bornstein 2012) Ingroup love is the main motivation

19. Main results so far 1.Lab experiments with minimal groups 2.Outgroup hate could be expressed only by harming the outgroup Weisel and Böhm (2015): 1. Natural groups with increasing degrees of enmity 2.Harm vs. help avoidance

20. Why natural groups? In real world intergroup conflict (e.g., between ethnic, religious, political groups): Group commitment is typically high Opposing groups are evaluated negatively Opposing groups are perceived as a severe threat Conflict can have a strong moral dimension Dortmund and Schalke fans

21. Pilot study – Football fans FC Carl Zeiss Jena cs. FC Rot-Weiß Erfurt Procedure: Match in Jena, December 16 th, 2011 Fans make a decision before the game During the game – matching and prepare payment Fans collect payment after the game

22. Hier Fragebogen ausfüllen! Was? Befragung unter FCC-Fans WIE LANGE? max. 5 Minuten WARUM? Chance auf Verdienst von über 100 Euro Unterstützung der Wissenschaft Mitmachen und Geld verdienen!

23. →You are in a group with 2 other fans of FC Carl Zeiss Jena ( ). →The 3 of you are matched with 3 fans of FC Rot-Weiß Erfurt ( ). →All of you will earn real money! →In the frame below there are three options that you can choose from. →Your choice has monetary consequences for yourself, for the 2 other members of your group, and for the 3 members of the other group. →The other members of your group and the members of the other group all have the same options to choose from, so they can affect your outcome, just like you can affect theirs. Read the instructions 1 Answer the following questions 3 Make your choice here 2 You +40 € +0 € Your group 0 € Other group You can earn up to 110€ by filling out this form! After collecting all forms, we will randomly select 6 people. Each one of these 6 people will be paid according to his/her decision and the decisions of the other 5, exactly as explained below. Please make your decision carefully, and remember that it can have real monetary consequences for you and for others. Very positive Slightly positive Neutral Slightly negative Negative Very negative Very positive Slightly positive Neutral Slightly negative Negative Very negative NothingVery littleSomeA lot Not at allA little bitSomewhatA lot You +20 € Your group 0 € Other group You +20 € Your group -20 € Other group → To what degree do you identify with the team FC Carl Zeiss Jena? → What is your attitude towards other fans of FC Carl Zeiss Jena? → What is your attitude towards other fans of FC Rot-Weiß Erfurt? → How much alcohol have you consumed today? Your answers to these questions will not affect your earnings. Please mark one option for each question. →Please mark one (and only one) option. →Your choice will determine your effect on the amount you, your group, and the other group will earn. →The numbers indicate the amount you will cause each person to earn (+) or lose (-). →You can also earn or lose money through the decisions of the others. →The final amount each person will earn will be determined by combining all 6 decisions, and adding a fixed amount of 50€. This is my choice

24. Ingroup love and outgroup hate in Morality-based groups (Parker and Janoff-Bulman 2013) Moral convictions are oppositional in nature In morality-based groups, ingroup identification seems fundamentally based on the existence of an outgroup Beliefs of the ingroup and the outgroup are oppositional Morality-rooted attitudes have more motivational force/action potential Intolerance, desire or social distance, low levels of cooperativeness “… moral social identities are a special classification of social group memberships in which outgroup ‘hate’ naturally co-exists with ingroup ‘love’”

25. Ingroup love and outgroup hate in Morality-based groups (Parker and Janoff-Bulman 2013) Morality based groups: Attitude regarding legal abortion (pro-life vs. pro choice) Political ideology (Liberals vs. Conservatives) Non-morality based groups: Sport fans (New York Yankees vs. Boston Red-Sox) University (University of Massachusetts vs. University of Conneticut) DV’s: Group based emotions (angry, happy, disgusted, respectful, fearful, positive, anxious, resentful, proud, hurt, sad, and negative) Perceived threat (e.g., “People who are fans of the Boston Red Sox threaten economic opportunities for others”)

26. Ingroup love and outgroup hate in Morality-based groups (Parker and Janoff-Bulman 2013) More positive emotions towards non-morality based ingroup More negative emotions towards morality based outgroup Mediated by perceived threat

27. Design (Weisel and Böhm 2015) Online-sample (N 1 =395, N 2 =1550), members of natural conflicting groups (fans of Bundesliga football clubs, supporters of German parties) 6 participants were selected for payment (in each study) Three degrees of enmity: no enmity, weak enmity, strong enmity (+ morality based groups) Three intergroup games: Intergroup Prisoner’s Dilemma (IPD) Intergroup Prisoner’s Dilemma – Maximizing Difference (IPD-MD) Positive variant of IPD-MD

28. Online-sample (N 1 =395, N 2 =1550), members of natural conflicting groups (fans of Bundesliga football clubs, supporters of German parties) 6 participants were selected for payment (in each study) Three degrees of enmity: no enmity, weak enmity, strong enmity (+ morality based groups) Three intergroup games: Intergroup Prisoner’s Dilemma (IPD) Intergroup Prisoner’s Dilemma – Maximizing Difference (IPD-MD) Positive variant of IPD-MD Design

29. Football clubs with varying degrees of enmity No enmity Weak enmity Strong enmity Borussia Dortmund FC Schalke 04 1. FC KölnBayer 04 Leverkusen

30. Football clubs with varying degrees of enmity Attitude towards members of other team [1 = very negative, 7 = very positive] No enmity outgroup Weak enmity outgroup Strong enmity outgroup M = 6.31 (SD = 1.02) M = 3.77 (SD = 1.04) M = 2.22 (SD = 1.28)

31. Political parties with varying degrees of enmity No enmity Weak enmity Strong enmity Free Democratic Party Christian Democratic Union The Greens Social Democratic Party

32. Political parties with varying degrees of enmity Social Democratic Party Christian Democratic Union Free Democratic Party The Greens No enmity Weak enmity Strong enmity “moral social identities are a special classification of social group memberships in which outgroup hate naturally co-exists with ingroup love” Parker & Janoff-Bulman 2013

33. Political parties with varying degrees of enmity Social Democratic Party Christian Democratic Union Free Democratic Party The Greens No enmity Weak enmity Strong enmity Morality based

34. Is NPD a morality-based outgroup? ›To what degree do you and supporters of … share similar moral values? (answered by supporters of four mainstream parties)

35. Attitudes towards party supporters Attitudes of row-party towards supporters of column-party GRUENECDUFDPNPDSPD GRUENE N=458 5.903.502.861.244.92 CDU N=498 3.745.654.181.474.18 FDP N=116 3.494.855.461.423.95 NPD N=13 3.294.003.863.933.64 SPD N=478 4.783.612.991.315.72

36. Attitudes towards party supporters Attitudes of row-party towards supporters of column-party GRUENECDUFDPNPDSPD GRUENE N=458 5.903.502.861.244.92 CDU N=498 3.745.654.181.474.18 FDP N=116 3.494.855.461.423.95 NPD N=13 3.294.003.863.933.64 SPD N=478 4.783.612.991.315.72

37. Political parties with varying degrees of enmity Attitude towards supporters of other party [1 = very negative, 7 = very positive] No enmity outgroup weak enmity outgroup strong enmity outgroup M = 5.73 (SD = 0.90) M = 4.65 (SD = 1.18) M = 3.49 (SD = 1.04) Football data M = 6.31 (SD = 1.02) M = 3.77 (SD = 1.04) M = 2.22 (SD = 1.28)

38. Why help-avoidance? Present day discrimination (in America) is primarily a result of selectively helping members of the advantaged groups, rather than harming members of disadvantaged groups (Greenwald and Pettigrew 2014, Banaji and Greenwald 2013) E.g., “wrong number” method (Gaertner and Bickman 1971) E.g., electric shock administration (Baron 1979) Positive-Negative Asymmetry of Social Discrimination (Mummendey and Otten 1998) No ingroup bias in negative outcome allocation (e.g., aversive noise) Ingroup bias in positive outcome allocation (e.g., money)

39. Games IPD – Intergroup Prisoner’s Dilemma Bornstein & Ben-Yossef, 1994 ›Two 3-player groups ›Each player receives an endowment of €40 ›IPD ›Keep: player receives €40 ›Contribute to within-group pool: each ingroup member receives 20 MU ›Contribute to between-group pool: each ingroup member receives €20 and each outgroup member loses €20 Ingroup love Outgroup hate

40. Games IPD-MD – Intergroup Prisoner’s Dilemma – Maximizing Difference Halevy, Bornstein, & Sagiv, 2008 ›Two 3-player groups ›Each player receives an endowment of €40 ›Negative IPD-MD ›Keep: player receives €40 ›Contribute to within-group pool: each ingroup member receives €20 ›Contribute to between-group pool: each ingroup member receives €20 and each outgroup member loses €20 Outgroup hate Ingroup love

41. Games IPD-MD – Intergroup Prisoner’s Dilemma – Maximizing Difference Halevy, Bornstein, & Sagiv, 2008 ›Two 3-player groups ›Each player receives an endowment of €40 ›Negative IPD-MD ›Keep: player receives €40 ›Contribute to within-group pool: each ingroup member receives €20 ›Contribute to between-group pool: each ingroup member receives €20 and each outgroup member loses €20 Outgroup hate Ingroup love

42. Games IPD-MD – Intergroup Prisoner’s Dilemma – Maximizing Difference Halevy, Bornstein, & Sagiv, 2008 ›Two 3-player groups ›Each player receives an endowment of €40 ›Positive IPD-MD ›Keep: player receives €40 ›Contribute to within-group pool: each ingroup member receives €20 ›Contribute to between-group pool: each ingroup member receives €20 and each outgroup member receives €20 Ingroup love Outgroup hate

43. Games

44. Decision screen – IPD You +20 € Your group -20 € Other group Option 2 You +40 € +0 € Your group +0 € Other group Option 1

45. Decision screen – IPD-MD You +20 € Your group -20 € Other group Option 3 You +20 € Your group +0 € Other group Option 2 You +40 € +0 € Your group +0 € Other group Option 1

46. Decision screen – Positive IPD-MD You +20 € Your group +20 € Other group Option 3 You +20 € Your group +0 € Other group Option 2 You +40 € +0 € Your group +0 € Other group Option 1

47. Hypotheses ›Both studies ›More overall contributions in IPD-MD (both versions) than IPD ›More enmity -> more outgroup hate ›More outgroup hate in the Positive IPD-MD than in IPD-MD ›Only study 2 ›More outgroup hate in interactions with a morality based outgroup

48. Results - Football More contribution in IPD-MD games (relative to IPD) More outgroup hate in Positive IPD-MD than in IPD-MD Degree of enmity matters only in Positive-IPD-MD

49. More contribution in IPD-MD games (relative to IPD) More outgroup hate in Positive IPD-MD than in IPD-MD Degree of enmity matters only in Positive IPD-MD Results - Football

50. Results – Political Parties Without Moral Conflict: More contribution in IPD-MD games (relative to IPD) More outgroup hate in Positive IPD-MD than IPD-MD Degree of enmity matters only in Positive IPD-MD

51. Results – Political Parties Without Moral Conflict: More contribution in IPD-MD games (relative to IPD) More outgroup hate in Positive IPD-MD than IPD-MD Degree of enmity matters only in Positive IPD-MD Less outgroup hate than in football study With Moral Conflict: A lot of outgroup hate

52. Results – Political Parties Without Moral Conflict: More contribution in IPD-MD games (relative to IPD) More outgroup hate in Positive IPD-MD than IPD-MD Degree of enmity matters only in Positive IPD-MD Less outgroup hate than in football study With Moral Conflict: A lot of outgroup hate – but only 50% in IPD-MD

53. Main results ›More outgroup hate in help-avoidance ›Degree of enmity related to outgroup hate only in help-avoidance ›Unless outgroup is morality-based ›Even then, only 50% of contributions in IPD-MD are outgroup hate

54. Implications Can be avoided if group members’ altruism is directed towards internal causes Even when enmity is high Harder to avoid Sensitive to degree of enmity Harming the other groupNot helping the other group

55. Negative and Positive Externalities in Intergroup Conflict (Weisel) Research questions: Consistency: Is behaviour consistent between settings where outgroup hate can be displayed by imposing negative externalities, and settings where it can be displayed by avoiding to impose positive externalities, on the outgroup? Order: Does the order in which people encounter situations in which they can display outgroup hate by imposing negative externalities, and by avoiding to impose positive externalities, affect behaviour? Groupness: What is the effect of peoples’ sense of groupness—the degree to which they care about their group and its well-being—on their willingness to display outgroup hate by imposing negative externalities, and/or by avoiding to impose positive externalities, on the outgroup?

56. Procedure 144 participants Cohorts of 12 3-person or 6-person groups Two decisions without feedback IPD-MD and Positive IPD-MD “Groupness” measure Social Value Orientation measure

57. Games

58. Groupness It is important to me to contribute to the group I am committed to contribute to the group It is important to me to act in favor of the group I want the group to do well

59. Results - Consistency

60. Results – Order Effects

61. Results - Groupness IPD-MD first: groupness related to both ingroup love and outgroup hate In both the initial IPD-MD and the subsequent Positive IPD-MD Positive IPD-MD first: groupness related only to ingroup love In both the initial Positive IPD-MD and the subsequent IPD-MD

62. Possible explanation for order effect First game encountered establishes a set of available actions. In the Positive IPD-MD, outgroup hate is associated with helping the ingroup only. The action is available in the IPD-MD as well, so the association carries on. In the IPD-MD, outgroup hate is associated with helping the ingroup and harming the outgroup. This action is not available in the Positive IPD-MD, so the association does not carry on.