Evolution of Discrimination (Experimental Ethics)

1. Evolution of Discrimination(Experimental Ethics) Chung Tue “DuCK” Nguyen BSE (Hon.) Project Supervisors: Ann Nicholson, Kevin Korb

2. Outline • Introduction & Motivation & Main goal • Related concepts • Experimental Design • The world • The agents • Observations & Results • Conclusion • References Evolution of Discrimination - Chung Tue "DuCK" Nguyen

3. Introduction & Motivation • Discrimination: • The ability to recognise differences. • The tendency to offer different treatement on the basis of those differences. • Positive: telling useful from harmful. • Negative: unfair treatement: racism, sexism, etc. • Does discrimination evolve? Evolution of Discrimination - Chung Tue "DuCK" Nguyen

4. Main goal • The goal of this study is: To observe the evolution of discriminatory tendencies in intelligent species through social interactions. Evolution of Discrimination - Chung Tue "DuCK" Nguyen

5. Related concepts • Evolutionary Theory • Natural selection – survival of the fittest • Evolutionary Psychology • Evolution of behaviours/mental traits • Baldwin Effect • Roles of learning in evolution • Ethocentrism • Ingroup hyper-evaluation • Outgroup negative streotype • Iterated Prisoner’s Dilemma (IPD) • Alife Simulation Evolution of Discrimination - Chung Tue "DuCK" Nguyen

6. Experimental Design • Using simulations to study discrimination • Standard Alife setup: • The world • The agents Evolution of Discrimination - Chung Tue "DuCK" Nguyen

7. The world • A wrap-around board of n-by-m locations • Each location can contain an infinite number of agents Evolution of Discrimination - Chung Tue "DuCK" Nguyen

8. The agent • Chromosome: mutable genotype • Behaviour: flexible phenotype • Discrimination is modelled using chromosome and behaviour Evolution of Discrimination - Chung Tue "DuCK" Nguyen

9. Chromosome vs Behaviour • Chromosome affects behaviour at birth. • Behaviour affects the tendency of possible actions. • Chromosome is modified through mutation. • Behaviour is modified through learning. • Social learning (mimic) • Individual learning (learning through pain/pleasure) Evolution of Discrimination - Chung Tue "DuCK" Nguyen

10. Chromosome, Behaviour and the Environment Evolution of Discrimination - Chung Tue "DuCK" Nguyen

11. Modelling discrimination • Chromosome: • “discrimination gene” • Behaviour: • “discriminatory behaviour” • Discrimination <-> Preference • Preferential genotype • Preferential behaviour • Measurable Evolution of Discrimination - Chung Tue "DuCK" Nguyen

12. Preferences • How positive/negative an agent “feels” about agents in his own group/the other group • Represenation: two numbers, each between 0 and 1 • Two types of preferences: • Ingroup preference: towards the ingroup • Outgroup preference: towards the outgroup • E.g.: Ingroup preference = 0.7, outgroup preference = 0.4 • Preferential behaviours <-> discriminatory actions Evolution of Discrimination - Chung Tue "DuCK" Nguyen

13. Preference test • Test for preference (ingroup/outgroup): • Choose randomly: x in [0,1] • Compare x with p • x <= p : like • x > p : dislike x =Test(preference) failure success Like p Dislike 0 1 Evolution of Discrimination - Chung Tue "DuCK" Nguyen

14. Main genotypes • Based on the values of preferences (chromosome), there are 5 main genotypes, each may evolve differently. Evolution of Discrimination - Chung Tue "DuCK" Nguyen

15. The agent (cont.) Other traits: • Race (can also be: religion, ideology, etc.) • Health • Age • Location • Fitness = #children + 2 x #grandchildren Evolution of Discrimination - Chung Tue "DuCK" Nguyen

16. A typical cycle • During 1 cycle of the simulation, every agent can perform all actions, in the following order: • Move • Learn socially (mimic the best) • Mate + reproduce • Interact + learn through pain and pleasure • Note: Agents don’t eat, health is affected directly through interaction Evolution of Discrimination - Chung Tue "DuCK" Nguyen

17. Preferences in action - Moving • Agents can move in four directions • Agents choose their location based on how much they like the majority of agents in a particular location. • Agents considers their current location as well as four cells around them. • Considerations are done in random order Evolution of Discrimination - Chung Tue "DuCK" Nguyen

18. Moving example In_pref = 0.8 Out_pref = 0.3 Majority = Red Test(Out_pref) = 0.4 Result: 0.4 > 0.3 => Failed In_pref = 0.8 Out_pref = 0.3 Majority = Blue Test(In_pref) = 0.6 Result: 0.6 > 0.8 => Success Note: much more likely to move in with its own kind Evolution of Discrimination - Chung Tue "DuCK" Nguyen

19. Preference in action – Social Learning (mimicking) • Agents learn from other agents in the same location • Agents learn from the race they like first • Agents learn from the agents the see as most successful (the idol) • Success = fitness x (maxAge – age) • Mimicking: • Depends on social learning success rate • Change preferences towards the idol’s preferences Evolution of Discrimination - Chung Tue "DuCK" Nguyen

20. Preference in action – Mating • There is no gender • Inter-racial mating • Mating is consensual • Consent is given on the basis of racial preference • I.e. both partners must pass the preference test • Mating hapens locally Evolution of Discrimination - Chung Tue "DuCK" Nguyen

21. Reproduction • When mating is successful, a new agent is created in the same location as its parents • New agent has a 50-50 chance of getting: • Either parent’s race • Either parent’s ingroup preference (chromosome), or mutate • Either parent’s outgroup preference (chromosome), or mutate • A small chance of mutation: • Change the value to any x in [0,1] Evolution of Discrimination - Chung Tue "DuCK" Nguyen

22. Reproduction example Chromosome: 0.3/0.5 Behaviour: 0.6/0.9 Chromosome: 0.6/0.4 Behaviour: 0.3/0.7 Chromosome: 0.6/0.4 Behaviour: 0.3/0.5 Evolution of Discrimination - Chung Tue "DuCK" Nguyen

23. Preference in action – Interaction & Indiv. Learning • Every agent interacts with another agent in the same location, randomly chosen. • Interaction is essentially an IPD* game: • Each agent does a preference test on the other • If success: the agent cooperates • If failure: the agent defects • Agent’s health is updated accordingly Evolution of Discrimination - Chung Tue "DuCK" Nguyen

24. Interaction trade-offs A typical IPD is characterised with the following order of trade-offs: • Defect – Cooperate • Cooperate – Cooperate • Defect – Defect • Cooperate – Defect Evolution of Discrimination - Chung Tue "DuCK" Nguyen

25. Learning through pleasure and pain • Agents change their preference according to the result of their interaction with another agent. • If Pleasure: increase preference • If Pain: decrease preference • Preference test also applies: • Only increase preference if success • Only decrease preference if failure Evolution of Discrimination - Chung Tue "DuCK" Nguyen

26. Experiments • Difference between genotypes • Relationship between fitness and preference • Relationship between ingroup and outgroup preference • Population development and geographical distribution of the races Evolution of Discrimination - Chung Tue "DuCK" Nguyen

27. Experimental modes • Separated communities: • Two races start in isolation • Mixed communities: • Two race mixed together from the start Evolution of Discrimination - Chung Tue "DuCK" Nguyen

28. Running the simulation • Run 30 simulations in each experimental mode • Each simulation is 1000-cycle long • Starting population is 7000 • World size: 50x50 • All agents start off as “Moderate”: • In_pref = Out_pref = 0.5 Evolution of Discrimination - Chung Tue "DuCK" Nguyen

29. Results - Overview • The genotypes did evolve • Order of fitness (most -> least): • Supremacist • Do-gooder • Hater • Betrayer • Ethnocentric behaviours • Most affected by the Supremacist and Do-gooder Evolution of Discrimination - Chung Tue "DuCK" Nguyen

30. Results - Overview • Separated communities different from mixed communities: • Separated: • Less variations in genotype • More variations in races • Complete domination + extinction • Mixed: • More variations in genotype • Less variations in races • Domination changes hands Evolution of Discrimination - Chung Tue "DuCK" Nguyen

31. Results - Experiment 1 • Difference between genotypes Separated communities Mixed communities Evolution of Discrimination - Chung Tue "DuCK" Nguyen

32. Results - Experiment 1 Separated communities Mixed communities Evolution of Discrimination - Chung Tue "DuCK" Nguyen

33. Results – Experiment 2 • Relationship between fitness and preference Separated communities Mixed communities Correlations: Inpref-Fitness = 0.887, p = 0.01 Outpref-Fitness = -0.519, p = 0.01 Correlations: Inpref-Fitness = 0.920, p = 0.01 Outpref-Fitness = -0.660, p = 0.01 Evolution of Discrimination - Chung Tue "DuCK" Nguyen

34. Results – Experiment 3 • Relationship between ingroup and outgroup preference Separated communities Mixed communities Correlations: Inpref-Outpref = -0.750, p = 0.01 Correlations: Inpref-Outpref = -0.951, p = 0.01 Evolution of Discrimination - Chung Tue "DuCK" Nguyen

35. Results – Experiment 3 Separated communities Mixed communities Correlation: Inpref-Outpref = 0.736, p = 0.01 Correlations: Inpref-Outpref = -0.774, p = 0.01 Evolution of Discrimination - Chung Tue "DuCK" Nguyen

36. Results – Experiment 4 • Population development and geographical distribution of the races Separated communities Mixed communities Evolution of Discrimination - Chung Tue "DuCK" Nguyen

37. Results – Experiment 4 Separated communities Mixed communities Clear domination: 46.6% Extinction: 0% Clear domination: 70% Extinction: 13.3% Evolution of Discrimination - Chung Tue "DuCK" Nguyen

38. Results – Experiment 4 Separated communities Mixed communities Evolution of Discrimination - Chung Tue "DuCK" Nguyen

39. Results – Experiment 4 Separated communities Mixed communities Evolution of Discrimination - Chung Tue "DuCK" Nguyen

40. Results – Experiment 4 • More geographical distribution if time permits… Evolution of Discrimination - Chung Tue "DuCK" Nguyen

41. Conclusion • Discrimination can be demonstrated to be evolutionary • A successful discriminatory strategy includes a reasonable level of cooperation and defection • Ingroup cooperation has more impact on fitness than outgroup defection: • don’t have to love thine neighbours • but don’t mess up with thine family • Ethnocentric behaviours may have been evolutionary • Mixed communities allow more variation and balanced competition. • Think: multiculturalism, immigration… Evolution of Discrimination - Chung Tue "DuCK" Nguyen

42. Futher work • More + longer simulation • Race domination will stabilised or lead to extinction eventually? • Increase separation space/time to observe development before and after contact (in separated communities mode) • More efficient simulation • Find a better way to observe geographical distribution of genotypes in 3D. • Thesis Evolution of Discrimination - Chung Tue "DuCK" Nguyen

43. References • Refer to References section in the Thesis Evolution of Discrimination - Chung Tue "DuCK" Nguyen

44. Questions? • Thank you. Evolution of Discrimination - Chung Tue "DuCK" Nguyen