Abstract
During Japan's Edo period, “yugaku" was the system of studying at “hanko" (higher education facilities for children of vassals) from outside a “han" (domain). This study demonstrates the influence of yugaku on the formation of the hanko ego-network. Network and statistical analyses were performed using 10 sets of hanko and han panel data (from 1736 to 1835). The result shows that although the increasing age of a hanko has a negative impact on the formulation of an ego-network, the degree of dedication to the yugaku of a han has a positive influence on it. These results indicate that although the reduction of an organization's environmental adaptability by age promotes a scale-down of the organization's ego-network, the degree of exploration expands it.