Agent-based simulation of ethnic prejudice transmission using Entorama tool

1. Agent-based simulation of ethnic prejudice transmission using Entorama tool Armano Srbljinović Ministry of Defence – Institute for Research and Development of Defence Systems, Zagreb, Croatia Vjekoslav Afrić Faculty of Humanities and Social Sciences University of Zagreb, Croatia Branimir Čače Faculty of Mechanical Engineering and Naval Architecture University of Zagreb, Croatia

2. Theoretical background Research hypotheses High-level description of the model Expected support from the model to the hypotheses Brief demonstration of the model using Entorama Outline Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

3. Relates contact between ethnic groups with prejudice within groups against members of other groups Contact theory • Gordon W. Allport: The Nature of Prejudice, 1954 • Thomas F. Pettigrew: Racially Separate or Together, 1971 Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

4. Contactamplifies or reduceseffects of other factors present in situations in which contact occurs The role of contact Contact Other factors Ethnic prejudice Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

5. Does not specify: Factors which might be influenced by contact Mechanisms by which contact influences other factors Unresolved issues of contact theory Contact ? ? Other factors Ethnic prejudice Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

6. Economic context as “an additional factor” of the contact theory Economic context impacts ethnic prejudice Contact moderates the influence of economic context Theoretical hypotheses Contact Economic context Ethnic prejudice Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

7. Empirical research (1) Higher levels of economic development reduce the likelihood of ethnic wars. (Sambanis, 2001) The occurrence of a recession increases the probability of internal conflict. (Blomberg and Hess, 2002) Contact theory itself (2) Prejudice is lessened when the two groups: possess equal status, seek common goals, are cooperatively dependent upon each other, interact with the positive support of authorities, laws, or customs. (Pettigrew, 1971) Support to the hypotheses Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

8. Can we get additional support using an agent-based simulation model ? Support to the hypotheses Agent-based model Contact Economic context Ethnic prejudice Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

9. Allows “playing with theories” without the need to interfere with real human subjects Particularly adequate for investigating micro-foundations of macro-phenomena Reasons for using AB modelling • Micro-sociological foundations of group movements and conflicts have been neglected in political science, mainly because the proper theoretical tools to investigate the motives and thoughts of individuals, as well as the mechanisms and conditions of group mobilization, are lacking. • (Bollerup and Christensen, 1997) Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

10. Dependent variable: ethnic prejudice Independent variables: level of contact, presence of economic context Basic experimental design Contact low high not present not present Economic context low high present present Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

11. 2 model settings: Basic “Pure” prejudice transmission model Corresponds to the absence of additional factors in contact theory Extended Prejudice transmission “embedded” in economic context Economic context as additional factor 2 ethnic segregation patterns: High segregation – corresponds to low contact Low segregation – corresponds to high contact Operationalization – the model Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

12. Agents of 2 ethnic groups: “blue” and “red” Main attribute: prejudice level Low, medium, or high Updated in each step by taking into account prejudice levels in an agent’s “socializing circle” “Socializing circle” of an agent A (fixed) group of other agents that an agent meets and has an opportunity to “interact with” Interaction = observing the prejudice level of the other agent Basic setting: prejudice transmission Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

13. Probability of interaction with a given agent from the socializing circle depends on: Ethnic membership of the given and the other agent Strength of the norm of exclusion within the given agent’s ethnic group Prejudice level of the given and the other agent Strength of the norm of exclusion Group parameter indicating the inclination of group members to ostracize Members of other groups Members of the own group who are not willing to ostracize members of other groups Operationalized as a proportion of agents with high prejudice level within an ethnic group Basic setting: prejudice transmission Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

14. Basic setting extended with a simple economy of exchange with unlimited resources (EoE-UR) Additional attribute: wealth Each interaction accompanied with a simple economic transaction which increases the wealth of the interacting agents by random amount between 0 and 1 Extended setting: economic transactions Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

15. If the wealth of the given agent is approximately equal to the wealth of the agents from the socializing circle: Prejudice level update is the same as in the basic setting If the wealth of the given agent is significantly less than the wealth of the agents from the socializing circle: The given agent is “dissatisfied” and “has an incentive to try a new form of behaviour” The new prejudice level of the given agent is chosen randomly Extended setting: economic transactions Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

16. High segregation/low contact: Blue agents spatially segregated from red agents Low segregation/high contact: Blue agents spatially interspersed with red agents Ethnic segregation patterns Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

17. (H0) No significant effects of contact on ethnic prejudice in the absence of additional factors (basic setting) (H1a) Negative effect of the EoE-UR on ethnic prejudice (H1b) Amplifying effect of contact: Stronger negative effect of the EoE-UR on ethnic prejudice when the contact is high, thanwhen the contact is low Operational hypotheses Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

18. In the segregated setting agents only meet more agents of the other colour, all other things being equal. Prejudice level depends mainly on the amount of prejudice in the surroundings: If the proportions of prejudiced agents in the socializing circles are approximately equal (irrespective of the prevailing colour), prejudice levels of agents will stay approximately equal.  Increased contact between groups will have no significant effect on prejudice. Micro-explanation – (H0) Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

19. Wealth increases with interaction Ideal-case assumption: unlimited resources, no competition Less prejudiced agents are “more open” - have more opportunities for interaction There is a clear incentive to become less prejudiced Micro-explanation – (H1a) Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

20. In the non-segregated setting, prejudiced agents interact less than in the segregated setting (less “brethren” in the surrounding) Prejudiced agents become less wealthy in the non-segregated setting than in the segregated setting There are more incentives to become less prejudiced in the non-segregated setting than in the segregated setting Stronger negative effect of the EoE-UR on ethnic prejudice in the non-segregated setting (when the contact is high) Micro-explanation – (H1b) Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

21. Initial proportion of prejudiced agents in the population Radius of the socializing circle Population density … Control variables Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

22. Implementation in Entorama Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool

23. Allport, Gordon W., 1954, The Nature of Prejudice, Addison-Wesley. Axelrod, Robert, 1997, The Complexity of Cooperation: Agent-Based Models of Competition and Collaboration, Princeton University Press. Blomberg, S. Brock and Gregory D. Hess, 2002, The Temporal Links between Conflict and Economic Activity, Journal of Conflict Resolution, 46(1), 74-90. Bollerup, Søren Rinder and Christian Dons Christensen, 1997, Nationalism in Eastern Europe: Causes and Consequences of the National Revivals and Conflicts in Late-Twentieth-Century Eastern Europe. Macmillan. Čače, Branimir, 2008, Entorama, http://www.entorama.com Forbes, Hugh D., 1997, Ethnic Conflict: Commerce, Culture, and the Contact Hypothesis, Yale University Press. Grim, Patrick, Evan Selinger, William Braynen, Robert Rosenberger, Randy Au, Nancy Louie and John Connolly, 2005, Modeling Prejudice Reduction: Spatialized Game Theory and the Contact Hypothesis, Public Affairs Quarterly, 19(2), 95-125. Hardin, Russell, 1997, One for All: The Logic of Group Conflict, 2nd edition, Princeton University Press. Pettigrew, Thomas F., 1971, Racially Separate or Together, McGraw-Hill. Sambanis, Nicholas, 2001, Do Ethnic and Non-Ethnic Civil Wars Have the Same Causes? A Theoretical and Empirical Inquiry (Part I), Journal of Conflict Resolution, 45(3), 259-282. Srbljinović, Armano, 2008, The Transition of a Multiethnic Community from Segregation to Cultural Pluralism, Doctoral thesis (in Croatian), University of Zagreb. References Srbljinović, Afrić, Čače: Agent-based simulation of ethnic prejudice transmission using Entorama tool