1. Ingroup Cooperation and Trust: Two Models Marilynn B. Brewer Ohio State University Sapporo, Japan September, 2003

2. Brewer & Kramer (1986) Effects of collective identity salience on cooperation in a resource dilemma: An anomaly

3. Resource Dilemma (Brewer & Kramer, 1986) Resource Pool S1 S2 S3 S4 S5 S6 S7 S8 “Replenishment” rate = 0.9 – 1.1

4. Resource Dilemma (Brewer & Kramer, 1986) Resource Pool S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 S16 S17 S19 S20

5. Experimental Design Group Size: 8 vs 32 Framing: Conservation dilemma vs Contribution dilemma (public goods) Identity salience: individual vs collective Time (feedback) Phase 1: gradual depletion (14 trials) Phase 2: depletion crisis (6 trials)

6. Results: Phase 1 First trial: Main effect of group size (M small = 13.15 vs M large = 14.42) Main effect of framing (M cons = 12.13 vs M cont = 15.45) Across trial blocks: Slight decline in take, especially in public goods (contribution) condition

7. Results: Phase 2 Conservation Frame Contribution Frame

8. Some More Recent Theorizing

9. Core Configurations (Caporael, 1997) Configuration SizePrototypeModal Task Dyad 2 Spouses; parent-child Sex; caregiving Work group 5-7 Hunting group; teams Foraging, hunting, crafts Deme 30 VillageFood sharing; migration Macrodeme 300 TribeSeasonal gatherings

10. Level of Analysis Self- Concept Basis of Self-esteem IndividualPersonalTraits and aptitudes Inter- personal RelationalRoles and relationships GroupCollectiveGroup welfare Levels of Self-Representation (Brewer & Gardner, 1996)

11. Two Models of Social Control Reciprocal exchange relationships interpersonal trust; internal differentiation Group-based collectivism depersonalized loyalty to group as a whole; entification and boundedness

12. A Nonintuitive Implication Individualism  Collectivism

13. Some Evidence… Americans score high on individualism but also on ingroup identification, value of belonging to groups (Oyserman et al., 2002; Yuki, 2003) Gender differences in relational versus collective interdependence (Kashima et al., 1995; Gabriel & Gardner, 1999)

14. Gender and Depersonalized Trust

15. More Direct Evidence (Buchan, Croson, & Dawes, 2002)

16. Social Value Orientation and the Ingroup Effect in Social Dilemmas (DeCremer & vanVugt, 1999) Ingroup Salience

17. Brewer & Kramer Revisited…