Unstable Ideas

In his most probing and expansive work to date, Jerome Kagan—one of this country’s leading psychologists—demonstrates that innovative research methods in the behavioral sciences and neurobiology, together with a renewed philosophical commitment to rigorous empiricism, are transforming our understanding of human behavior. Contemporary psychology, according to Kagan, has been preoccupied with three central themes: How malleable is temperament? How predictable are the milestones of cognitive development? How accurate is consciousness as a window onto the self, its motives, beliefs, and emotions?In a review of past approaches to these questions, Kagan argues persuasively that behavioral scientists have reached less-than-satisfactory answers because they have failed to appreciate the biases inherent in their frame of reference and the limitations of their investigative procedures. He calls into question a number of techniques that have been mainstays of psychological investigation: the Ainsworth Strange Situation for assessing the emotional attachment of an infant to its mother, and interviews and questionnaires as indexes of personality, to name only two. Kagan’s own research has used novel laboratory situations to discover a group of children who exhibit a pattern of behavior he calls “temperamentally inhibited”—they are restless and irritable from birth, and by twenty-four months cling to the mother and show biological signs of high anxiety in unfamiliar situations.These findings, coupled with current understanding of the structure and chemistry of the nervous system, lead him to speculate that these children are born with a biological predisposition that favors the development of a shy, fearful personality. Through longitudinal studies of this kind, as well as through his cross-cultural investigations of cognitive development, Kagan has infused new meaning into the nature–nurture debate.

Jerome Kagan…sets forth an elegantly reasoned and well-written argument for events, functions, and dynamisms rather than things as explanatory notions in psychology. What he calls for is a more complex understanding of the interaction between personality and environment—and the master concept through which he explores such interaction is the notion of ‘temperament.’, Kagan weaves philosophy, physics, and psychology into a persuasive…form. His book should be required reading for anyone concerned with our children, or who they become., The author marshals vast erudition and scholarship… The domain [Kagan] surveys in this series of essays is vast. It includes trends in developmental psychology across the twentieth century; it takes in the cognition, temperament, and self of his subtitle, and touches as well on issues of epistemology, methodology, morality and ethics, and creativity in science… This is a book of varied, sometimes far-flung, themes developed in an integrated and unified manner. It is an ambitious undertaking, but the author realizes his intentions admirably, even spectacularly.

Jerome Kagan was Daniel and Amy Starch Research Professor of Psychology Emeritus at Harvard University.