The First Longitudinal Study of Attachment in Japan: A Partial Replication of Main Et al.’s 1985 Work

Main, Kaplan, and Cassidy profoundly shifted the direction of attachment research with the publication of the paper “Security in infancy, childhood, and adulthood: A move to the level of representation.” Although collaborators played a critical role, it was primarily Mary Main’s natural curiosity and creativity that drove the expansion of attachment measurement boundaries. The new attachment measures extended beyond infancy and behavior, reshaping the concept of individual differences in attachment status by focusing on distinctions in internal working models (IWM) of the self in relation to attachment figures. These models were understood to be shaped by implicit rules established consciously or unconsciously, predominantly evolving out of attachment-related experiences. To commemorate Main’s remarkable accomplishment, we present a brief longitudinal study that applies the measures from her pioneering work to the culturally diverse context of Japan. This is the first longitudinal study of attachment—albeit exploratory—conducted in Japan. The results showed that, in Japan, behavioral measures did not predict the continuity of attachment security versus insecurity from infancy to age six. A significant association, however, was found via measures of representation. Strong correlations between mothers’ state of mind and child security were, however, observed in infancy and at age six. Implications of the findings with cultural considerations are discussed.