1. Synchrony & Cooperation Scott S. Wiltermuth and Chip Heath

2. Purpose The authors suggest that acting in synchrony with others can foster cooperation within groups by strengthening group cohesion.

3. Synchrony Occurs when people move in time with one another Cultural practices: 1.Armies 2.Churches 3.Communities 4.Organizations

4. Current theories Muscular bonding (McNeill, 1995) Mediated by positive emotions Ehrenreich, 2006; Hannah, 1997 Collective effervescence

5. Collective Effervescence Andaman Islanders: become absorbed in the unified community through dance (Radcliffe-Brown, 1992) http://www.youtube.com/watch?v=OcFEjpn8SlU

6. Andaman Islanders Out-of-Africa Migration (Wade, 2006)

7. Collective Effervescence Modern examples: 1.Carnival revelers (Ehrenreich, 2006) 2.Ravers (Olaveson, 2004) What are some others?

8. A lack of evidence… A causal linkage from synchrony to group cohesion. What types of synchrony promote cohesion? Necessity of collective effervescence.

9. Hypotheses Synchrony-cooperation hypothesis Muscular-bonding hypothesis “Collective effervescence” hypothesis

10. Study 1 Purpose: Can synchrony boost cooperation and cohesion? 30 participants: Groups of 3 Phase I: Campus Walk Two conditions: synchrony vs. control Phase II: Weak Link Coordination Exercise Phase III: Questionnaire

11. Weak Link Coordination Exercise Measures expectations of cooperation

12. Study 1: Questions How connected did you feel with the other participants during the walk? How much did you trust the other participants going into the exercise? How happy do you feel?

13. Study 1: Results Synchrony-cooperation hypothesis Synchronous condition chose higher numbers in the first round Synchrony-cohesion hypothesis Synchronous condition felt more connected with their counterparts Collective effervescence hypothesis Synchronous condition did not feel happier

14. Study 2 Purpose: Can synchrony boost cooperation above common identity and common fate? 96 participants: Groups of 3 Phase I: Cups-and-music task Four Conditions Phase II: Weak Link Coordination Exercise Phase III: Questionnaire

15. Cups-and-music task Listening to “O Canada” and holding a cup Four conditions 1.No singing, no moving (Control) 2.Synchronous-singing (SS) 3.Synchronous-singing-and-moving (SSM) 4.Asynchronous-singing-and-moving (ASM)

16. Study 2: Questions How much did you feel you were on the same team as the other participants? How much did you trust the other participants going into the exercise? How similar are you to the other participants? How happy are you right now?

17. Study 2: Results Muscular-bonding hypothesis Cooperation did not differ between SS and SSM

18. Study 2: Results Synchrony-cooperation hypothesis In Round 1 and the final round, SS and SSM chose: Significantly higher numbers than ASM Marginally higher numbers than Control

19. Study 2: Results Synchrony-cohesion hypothesis SS and SSM reported greater feelings of being on the same team Collective effervescence hypothesis Synchronous condition did not feel happier Payoffs SS and SSM received higher payoffs than did ASM or Control

20. Study 3 Purpose: Can moving in synchrony boost cooperation when behaving cooperatively conflicts with personal self-interest? 95 participants: Groups of 3 Phase I: Cups-and-music task Phase II: Public-Goods Game Phase III: Questionnaire (Study 2)

21. Public-Goods Game Each of three participants has 10 tokens in each of 5 rounds Public account - $0.25 to each member Private account - $0.50 to private member Dominant strategy is to behave selfishly

22. Study 3: Results Synchrony-cooperation hypothesis SS and SSM contributed marginally more tokens in Round 1 and significantly more in all subsequent rounds than: ASM Control (except Round 5)

23. Study 3: Results Over time SS and SSM persisted while ASM contributed significantly less tokens from first to last round

24. Study 3: Results Synchrony-cohesion hypothesis SS and SSM reported greater feelings of being on the same team Partially mediated the effect of conditions on contributions Rounds 3 & 5

25. Study 3: Results Payoffs SS and SSM received higher payoffs than did ASM or Control Similarity and Trust SS and SSM felt more similar to their counterparts than did ASM and trusted them marginally more Collective effervescence hypothesis SS and ssm did not feel happier

26. Conclusion Acting in synchrony with others can increase cohesion and cooperation. Muscular-bonding and collective effervescence hypotheses were not supported. Evolutionary implications

27. Synchrony in the Andes Synchronous rituals Rugby – prior to the crash Prayer – following the crash Provided this evidence, synchrony may have contributed to the strong cohesiveness and cooperation that allowed these individuals to survive such extreme circumstances.