"How do I Know Thee: A Simulation Study of Direct and Third Party 
Information on Social Network Evolution"

ABSTRACT
Granovetter (1985) challenged traditional views of the analysis of 
cooperation.  He claims that most approaches are either under-
socialized (peers play no role) or over-socialized (institutions and 
central authorities play an overwhelming role).  In this study we 
pursue the consequences of cooperation embeddeded in a social context 
on the evolution of social networks.  We identify two strongly 
distinct patterns of social networks.  Most surprisingly, we find that 
strong commitments to using social sources of information generate 
group polarization, while strong commitments to information arising 
from individual experience lead to integration among groups.  Given 
that many studies of cooperation assume the structures in which actors 
function, this work helps to identify the micro-behaviors that create 
the structures that constrain or enable cooperation.