Adolescence is a period of marked change in the person's cognitive, physical, psychological, and social development and in the individual's relations with the people and institutions of the social world. These changes place adaptational demands on adolescents, ones involving relations between their actions upon the context and the action of the…

This article reviews Giyoo Hatano's ground-breaking theoretical, empirical, and methodological contributions to conceptual change research. In particular, his discovery of "vitalism" as part of children's legitimate and distinctive biology at early ages stands as a landmark. In addition, his work reinterpreted childhood "personification," changing…

This paper builds on Hatano and Inagaki's pioneering work on the role of experience and cultural models in children's biological reasoning. We use a category-based induction task to consider how experience and cultural models shape rural and urban children's patterns of biological reasoning. We discuss the implications of these findings for…

Through the application of life course theory to the study of sexual orientation, this paper specifies a new paradigm for research on human sexual orientation that seeks to reconcile divisions among biological, social science, and humanistic paradigms. Recognizing the historical, social, and cultural relativity of human development, this paradigm…

The classical attachment theory holds to the notion of a monotropic model. Such a model leads to a view of the mother as first and most important figure in an infant's life. A polytropic view of attachment moves us toward a model of simultaneous and multiple attachment figures. In particular, it is argued that peer attachment is a separate but…

This article addresses how close relationships can be conceptualized so that they can be accurately understood over the life span. First, two typical clusters of theories of close relationships, the attachment theory and the social network theory, are compared and discussed with regard to their fundamental but controversial assumptions regarding…