Information  Transmission  and  Formation  of  Institutions in Socially Developmental  Individuals  


      This paper proposes a model of social individual and agent-based simulations for the formation  
of  institutions. No individual in any society lives isolately. This statement means that any 
individuals  are influenced by others not only at making decision but in developmental process.  
However, the  latter effect is limitedly treated in models of individuals in social sciences. The 
model  of an  individual in our proposal has a cognitive framework that develops under the 
influence of others'  behaviour. The framework is used to interpret signals given to the individual. 
Thus, it determines a  way of thinking.  This paper presents several simulations based on this basic 
model of individual. Their common  feature is that two kind of individuals, information senders and 
receivers, transmit information about  some events in one way.  This setup comes form the fact 
that most people in the modern society  cannot have firsthand information and interpret signals 
interpreted by others beforehand. The  performance of receivers' interpretations depends on how 
they are consonant with results of the  events. The receivers may or may not modify their 
framework and change their information senders  according to the performance.  
		
      The simulations differ in settings of the cognitive frameworks and the way to make the result of  
the event. While, in the simplest setting, signals are interpreted independently, the correlation 
among  bits in the process of interpretation is incorporated in another setting. A result of events 
are either  given from the outside, that is, independent from the interpretations, or constructed 
socially using the  receivers' interpretations. 
		
      We observe in all the settings the formation of clusters in which the receivers adopt the same  
sender.  The frameworks of the receivers in one cluster accord with each other. It is thought of as  
establishing institutions in which a way of thinking is regulated, since in a cluster any receivers with  
different framework decline their performance. The size of the clusters depends as a power law on  
the strength of interaction among the receivers. This result suggests that institutions may 
organized  in a society even  with  weak interaction.  When results are externally determined, the 
whole  system falls into one cluster, while the system is divided into several clusters if results are  
determined socially. Concerning the process of formation of clusters, punctuated equilibria are  
observed when mistakes in interpretations are introduced to the model of correlative interpretation.  
Frequency of mistakes affects the process and the consequence of cluster formation. We analyze 
this  phenomena using the notion of error threshold.