748.5
Mysteries of the Discourses That Encourage Cooperation. Ver.2
- Another important constant number on the human societies added to “Dunbar’s Number”?-
Yoshio Sakurai
（Kagoshima University）
yoshiosakuraig@gmail.com
[Introduction] We found some phenomena after 3.11 which had almost not been expected earlier. I would like to have attention to a phenomenon of “speeches advocating cooperation”.
[Methods] I use a multi agent simulator. The structure of the pay-off of the game is composed by a kind of ‘social dilemma’ in her neighborhood, and other orientations with their costs. Each agent has a strategy which has two kinds of output values; [act cooperatively / act not cooperatively] and [speak to advocate cooperation /not speak]. There is also another parameter, ‘threshold for speaking to advocate cooperation’ parameter. Each agent will speak to advocate cooperation with ‘a cost’; when and only when the ‘cooperative actor rate ’ of her neighborhood is UNDER her ‘threshold for speaking to advocate cooperation’ parameter.
[Results/Conclusion] I tried to check whether “speaking to advocate cooperation” or “not speaking to advocate cooperation ” has effects on the cooperators rates in the whole universe. The results are in Fig.1. Next, I tried a parameter survey on how values of the ’neighborhood radius’ have effects on the cooperators rates. I did 100 trials where the ’neighborhood radius’ were randomized with equal probability from 0 to 130. The result is in Fig.2. As the figure shows, in the cases that the ‘neighborhood radius’ ranges from 10 to 25, the ‘cooperators rate’s seem to be distinctly high. It seems that there is a ‘threshold value’ around 25 by which the ‘cooperators rate’s are discriminated between being high and being nearly zero. I think that these models are interesting in several points. We will discuss some at our conference.