1. Leap of Faith vs. Testing the Water Incremental Approach to Solidarity in Dyadic Exchange Ko Kuwabara (Columbia University) Oliver Sheldon (Rutgers University)

2. Solidarity from Exchange Which exchange pattern produces more solidarity (trust and cohesion)?  Constant exchange: Always giving the same (full) amount  Incremental exchange: Gradually giving more and more

3. Mixed Results People “prefer” incremental exchange (Kurzban et al. 2008; Cook et al. 2005) Incremental exchange is evolutionarily stable (Roberts & Sheratt 1998) Gradual commitment produces more trust (Molm et al. 2000) But… Less than full entrustment signifies distrust (Pillutla et al. 2003) Early non-cooperation is particularly harmful (Lount et al. 2008)

4. From Exchanges to Relationship Repeating exchanges successfully strengthens relational bonds.  When/How do interactions become a relationship? (Lawler 2000; Molm 2007) 1. Exchange produces emotions 2. Emotions attributed to different units of exchange Attributions to the other person creates trust (interpersonal bonds) Attributions to the relationship creates cohesion (relational bonds) 3. Covariation Model of Attribution (Kelly 1973) Consistent patterns invoke dispositional inferences Patterns that vary across time/space invoke external attributions

5. Overview of Studies STUDY 1. Exchange patterns in entrustment size (How much) STUDY 2. Exchange patterns in entrustment frequency (How often) STUDY 3. Entrustment frequency X entrustment size PREDICTIONS/FINDINGS 1. Exchanging incrementally in size produces more cohesion 2. Exchanging incrementally in frequency produces less cohesion Lower number of interactions (Lawler et al. 1992-2007) Lower rate of interactions (Molm et al. 2007) Early non-cooperation is particularly damaging (Lount et al 2008) 3. Frequency moderates size: Exchange pattern in size matters only when exchanges are sufficiently frequent.

6. Experimental Procedures Exchange task  Gift exchange (repeated and alternating dictator game)  Exchange decision in each round to send X points to P Remaining amount invested in lottery Entrustments between P and P multiplied by 1.5 (return from exchange) Lottery: 50% chance of x1.5 pts, 50% chance of x1 pts Procedures  Play 30-50 rounds of exchange games with an anonymous partner (simulated to follow pre-programmed exchange patterns)  Last round announced: Entrustment in end-game  Complete a post-experimental questionnaire about trust and cohesion How much trust/distrust do you feel toward your partner? How positive/negative do you feel about the relationship?

7. Manipulations The simulated partner was programmed to... Constant exchange: Offer full (100%) entrustments in every round. Incremental exchange: Offer 35-40% of endowment (or give full endowment at 35-40% probability) in each round in the beginning, gradually increasing to full and constant entrustment by the mid-point of the exchange rounds.

8. Study 1: Entrustment Size No difference in trust (incremental exchange produced as much trust) Greater cohesion from incremental exchange More entrustment in last round after incremental exchange

9. Study 2 Incremental exchange in frequency reduced trust, cohesion, and entrustment in last round.

10. Study 3 Frequency has a positive main effect (on trust and cohesion) Incremental exchange in size promotes cohesion when exchange frequency is constant/high.

11. Conclusion Exchanging incrementally in size can promote cohesion, but only when exchange frequency is sufficient. More attention on exchange dynamics  Boundary conditions on rate of increment & initial level of exchange  How much exchange frequency is “sufficient”?  Are present findings generalizable to other exchange forms?

12. Exchange Patterns STUDY 1. Exchanging incrementally in entrustment size produces higher levels of cohesion STUDY 2. Exchanging incrementally in entrustment frequency is less likely to promote cohesion  Lower number of interactions (Lawler et al. 2000)  Lower rate of interactions (Molm et al. 2007)  Early non-cooperation is particularly damaging (Lount et al 2008) STUDY 3: Entrustment frequency moderates incremental exchange in entrustment size.  Relational attributions do not occur without sufficient interactions.

13. Study 3 Does size interact with frequency? 2 (size: constant vs. incremental) X 2 (frequency: constant vs. incremental) design

14. Study 2 Manipulated entrustment frequency Entrustments were binary (give or not give) Added a third condition (“incremental-long”) with additional rounds of full exchange to control for total number of exchange occurrences

15. Study 2 Incremental exchange in frequency reduced trust, cohesion, and entrustment in last round. Controlling for number of exchange occurrences had no effect.