|Title:||Pitfalls in Spatial Modelling of Ethnocentrism|
There is an increasing interest in using search heuristics to test and find solutions to problems in the place of analytical solutions and deterministic algorithms, probably due to the accessibility and ease of studying emergent phenomena in complex models. However, what we gain in tractable complexity, we lose in clarity. This paper is a case study of an agent-based model by Hammond and Axelrod studying the evolution of tag-based co-operation – "ethnocentrism" – with a focus on the consequences of assuming a lattice structure in which agents are located and with strict spatial rules for how they reproduce. It is shown that the spatial structure is what drives the results, rather than the phenomenon that is under study.
These findings illustrate the importance of scrutinising the assumptions and verifying the robustness of each assumption in the algorithm when we move away from analytical tractability and use search heuristics rather than deterministic algorithms, in specifically illustrating how spatial assumptions can alter a model to the extent that it no longer describes the phenomenon under study. Given that the kind of lattice structure in the case study is common in agent-based evolutionary algorithms, the problems highlighted here may have far-reaching consequences. This paper suggests methods for verifying the validity of such algorithms.
|Prel. end date:||2015-06-04|
|Student:||Fredrik Jansson email@example.com|