The Long Shadow of Temperament

Jerome Kagan and Nancy Snidman resolve many puzzling observations and theoretical controversies about the importance of innate vs. environmental factors in child development, in a book that is both intellectually satisfying and a pleasure to read. The Long Shadow of Temperament is a great delight. -- John T. Cacioppo, Tiffany and Margaret Blake Distinguished Service Professor, Department of Psychology, The University of Chicago Jerome Kagan is one of the major thinkers in developmental psychology today and a new book by him is always to be welcomed. He has always taken provocative positions and he does it so well that his readers rethink their old ideas and look at the world in a new way. -- Michael Rutter, Professor of Developmental Psychopathology, Institute of Psychiatry, King's College London For forty years, Jerome Kagan and his colleagues have done research that has allowed us to follow children's lives over time. In this new book with Nancy Snidman, he traces children's temperament and personality, from their reactivity in early infancy to their behavior and biology at age eleven. The reader will find surprising outcomes and exciting new links between psychology and biology that will be sure to influence future research in psychology. -- Mary K. Rothbart Distinguished Professor Emerita of Psychology, University of Oregon A highly readable and comprehensive summary of a remarkable twenty-five year program of research on the nature and consequences of temperament. Broad, incisive and provocative, this volume should be mandatory reading for any student of development, personality or psychopathology. -- Richard J. Davidson, William James and Vilas Research Professor of Psychology and Psychiatry, University of Wisconsin-Madison

Kagan and Snidman summarize the results of this unique inquiry into human temperaments, one of the best-known longitudinal studies in developmental psychology. These results reveal how deeply certain fundamental temperamental biases can be preserved over development.

We have seen these children—the shy and the sociable, the cautious and the daring—and wondered what makes one avoid new experience and another avidly pursue it. At the crux of the issue surrounding the contribution of nature to development is the study that Jerome Kagan and his colleagues have been conducting for more than two decades. In The Long Shadow of Temperament, Kagan and Nancy Snidman summarize the results of this unique inquiry into human temperaments, one of the best-known longitudinal studies in developmental psychology. These results reveal how deeply certain fundamental temperamental biases can be preserved over development.

Identifying two extreme temperamental types—inhibited and uninhibited in childhood, and high-reactive and low-reactive in very young babies—Kagan and his colleagues returned to these children as adolescents. Surprisingly, one of the temperaments revealed in infancy predicted a cautious, fearful personality in early childhood and a dour mood in adolescence. The other bias predicted a bold childhood personality and an exuberant, sanguine mood in adolescence. These personalities were matched by different biological properties. In a masterly summary of their wide-ranging exploration, Kagan and Snidman conclude that these two temperaments are the result of inherited biologies probably rooted in the differential excitability of particular brain structures. Though the authors appreciate that temperamental tendencies can be modified by experience, this compelling work—an empirical and conceptual tour-de-force—shows how long the shadow of temperament is cast over psychological development.