Journal on Policy and Complex Systems
2.4 Submodels
Diffusion of the Agriculture Rule : The diffusion of agriculture occurred through neighboring agents and inheritance from a father agent . In our simulation model , we assumed that these very simple patterns of cultural transmission followed the conventional susceptible – infectious ( SI ) model of infectious diseases .
In the diffusion from a neighboring agent , if the agent ’ s food production system was hunting and gathering , while that of all the other neighboring agents was agriculture within a given cell radius ( the extent of diffusion occurring within a cell range was : one cell [ narrow ], three cells [ moderate ], and five cells [ wide ]), the agent ’ s food production system would then be transformed into agriculture . This transformation was based on a given probability ( introduction rate : difficult 0.1 %, middle 0.5 %, and easy 1.0 %). Conversely , in the inheritance from a father agent , and according to the marriage rule described ahead , when a new agent ( child ) was created ( born ), the agent inherited the food production system from their father agent .
Diffusion of the Pottery Style : The diffusion of pottery style occurred through the vertical transmission from a mother agent and the horizontal transmission from a neighboring agent . In the vertical transmission , as mentioned above , the argument made by Tsude ( 1982 ) that women produced pottery during the Yayoi period is supported by an extensive ethnographic literature ( Murdok & Provost , 1973 ). Therefore , within the field of Japanese archeology , it has generally been held that women produced pottery during ancient times . Therefore , in our simulation model , the vertical transmission is the inheritance from a mother agent . In the horizontal transmission , this is reversible , that is , there are changes not only from the native style to the immigrant style , but also from the immigrant style to the native style . Specifically , the agent ’ s pottery style would change to another pottery style used by a different agent within a given cell radius ( the extent of diffusion occurring within a cell range was : one cell [ narrow ], three cells [ moderate ], and five cells [ wide ]). This transformation was also based on a given probability ( introduction rate : impossible 0 %, difficult 0.1 %, middle 0.5 %, and easy 1.0 %).
In summary , we simulate two pottery-style diffusion patterns : ( 1 ) maternal vertical transmission pattern and ( 2 ) vertical and horizontal transmission pattern .
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