Policy and Complex Systems
local visibility from their position as determined by this attribute setting .
To avoid bias , the model has the same rule structure for all agents . While it is possible to add a wide variety of interaction rules , the model includes only the simplest possible set of rules , leaving layers of complexity to future implementations .
Interaction Rules
These rules form the foundation for agent adaptation . Their simplified nature makes it possible to identify micro-level sources of emergent properties . In every simulation cycle , agents individually follow the procedure below :
Agent n identifies the most Influential agent with its same Identity in its radius of sight .
If there exists such an agent , and its Influence is higher than that of Agent n , it is identified as Agent x . Agent n updates its Ideology according to the following formula :
New Ideology Agent n = Old Ideology Agent n
+
( Ideology Agentx - Old Ideology Agent n
) *
Susceptibility Agent n
This means an agent ’ s change in Ideology in the presence of a more influential agent from its own group , is directly proportional to its Susceptibility .
1 . Next , Agent n checks to see if New
Ideology Agent n
> Threshold to Act Agent , and if this is true , Agent n kills all n agents from the other identity group in its radius of sight .
2 . Finally , every agent has an equal probability of reproducing in each model cycle . A new agent attributes are initialized according to the same structure specified above except for the Identity attribute , which is inherited from its parent agent .
These attributes and rules are the minimum set required to simulate genocide in an ABM in the context of the system view outlined in Figure 2 . While other starting points were possible , the works of Waller ( 2001 ) and Straus ( 2012a , & 2012b ) greatly informed the selected initial model components . Straus helped define the system system-level understanding , and Waller ( 2001 ) provided support for key elements of Straus ’ model , such as the presence of an extreme ideology . His focus on the psychological dynamics in the environmental presence of an extreme ideology with respect to the other guided the selection of an ABM with the above parameters for this initial implementation .
Early Results — ABM
Experiment 1 — Baseline Model Behavior
Given the above initialization , the first experiment determines the baseline behavior of the model . The analysis below is for the Base Model as described above , along with the following initial settings :
Populations : 50 agents each from Group A and Group B .
Radius of Sight : Five patches for all agents .
Reproduction : An agent has a 1 / 10 probability of reproduction if it has less than 10 agents of its own identity within its Radius of Sight .
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