NetLogo User Community Models
BRADFORD LEVIATHAN MODEL SHORT 7-4-14
by John Bradford (Submitted: 08/08/2014)
## WHAT IS IT?
Deffuant, Guillaume, Timoteo Carletti, and Sylvie Huet. “The Leviathan Model: Absolute Dominance, Generalised Distrust, Small Worlds and Other Patterns Emerging from Combining Vanity with Opinion Propagation.” Journal of Artificial Societies and Social Simulation 16, no. 1 (2012): 5. Available here: http://jasss.soc.surrey.ac.uk/16/1/5.html
Here is a copy of the abstract: "We propose an opinion dynamics model that combines processes of vanity and opinion propagation. The interactions take place between randomly chosen pairs. During an interaction, the agents propagate their opinions about themselves and about other people they know. Moreover, each individual is subject to vanity: if her interlocutor seems to value her highly, then she increases her opinion about this interlocutor. On the contrary she tends to decrease her opinion about those who seem to undervalue her. The combination of these dynamics with the hypothesis that the opinion propagation is more efficient when coming from highly valued individuals, leads to different patterns when varying the parameters. For instance, for some parameters the positive opinion links between individuals generate a small world network. In one of the patterns, absolute dominance of one agent alternates with a state of generalised distrust, where all agents have a very low opinion of all the others (including themselves)."
Each agent has a list of opinions about herself and other agents, ranging from -1 to +1. In this version, the parameter "condition" establishes the potential partners of each agent: global = all agents; local = agents within "influence_range"; and "small worlds" (see below).
NOTE: The article expresses the influence of j on i using the subscripts ij. Here, I use the subscript ij to express the influence of i on j.
STEP 1: Opinion Propagation.
The influence of j on i for i's self-regard is expressed as follows:
STEP 2: REPUTATION
STEP 3: VANITY DYNAMICS.
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