Review of Child Temperament: New Thinking About the Boundary Between Traits and Illness,by David Rettew

Temperament is a very messy topic. Suppose we reduce human behavior to a simple automotive model, in which the accelerator drives the initiation of a behavior, the fuel line maintains behavior once it starts, and brakes stop behavior. “Temperament” refers to individuals' “tendencies” to differentially implement these functions under a given set of external conditions. It is difficult enough with cars, but for humans, rather than having a system whereby we specify how quickly an individual applies the brake on a wet surface when viewing a stopped vehicle 50 meters ahead, we typically operationalize temperament by asking a question such as “does this person tend to be overly cautious?” Sometimes this serves as a reasonable proxy for temperament, other times not. In this book, Rettew breaks it all down and derives a sensible and practical working model for this elusive but critical sphere of influence on human behavior.

The book begins with a history of scientific attempts to characterize innate stimulus-response characteristics of human beings, and how a diverse set of investigative approaches – sometimes implementing highly imperfect questions, sometimes tracing the continuity of temperament traits over time, sometimes distilling new insights by tracking which tendencies “travel together” when more than one is measured, sometimes implementing genetically or biologically invormative designs that allow differentiation of nature and nurture – has converged upon a small number of primary dimensions of temperament that represent a sensible point of departure for modern behavioral neuroscience, clinical care, and, refreshingly, even parenting. The “big three” Rettew concludes, are negative emotionality, a child's proneness to experience negative emotions such as anxiety, sadness, or anger; extraversion, a child's tendency to engage the world and people around him/her; and regulatory ability, the capacity to regulate emotion and attention and to “rein in” overreaction when it would otherwise result in maladaptive responses to changes in the environment. The book proceeds to describe advances in understanding of the relationship between temperament and psychopathology, how extremes (high or low) in the big three confer susceptibilities to psychiatric disorders, especially when other genetic or environmental risk factors for those conditions are at play. Moderation in each of the big three can be key to successful interpersonal adaptation, and Rettew astutely proposes the “yet” conceptualizatio: that when asked to describe a temperamental ideal, the word “yet” typically enters our parlance: “… we want someone who can be spontaneous yet responsible, sensitive yet assertive, a good talker yet a good listener.”

The entire second half of the book is devoted to practical applications, and most notably summarizes these in a series of extremely informative tables. A first outlines how characterization of a pediatric patient's temperament can inform recommendations to that patient's “village” (family members, friends, and educators) about how to adopt supportive approaches that match that child's temperamental tendencies in a way that he predicts will yield the best results from those supports. Next is a temperament-informed outline for guiding parents in the implementation of skills such as coaching, ignoring, modeling, shielding, and adopting a united stance at home. Here the critical characteristics of parenting style – operationalized as high or low on the respective axes of warmth and control – are discussed in detail, as they can either facilitate relational support or collide with child temperament characteristics in very negative ways. The book provides very specific and practical guidance on avoiding vicious behavioral cycles, and serves gentle warning about ways in which extreme profiles of temperament in childhood tend to elicit highly counterproductive responses from certain types of parents. For the all-important school environment, there follows a summary of suggestions for both “helping the child fit the school” and “helping the school fit the child.”

This volume is exhaustively referenced and constitutes a primer for understanding the enduring behavioral tendencies encompassed by modern conceptualizations of temperament. Although the book's subtitle refers to the important gray zone between traits and illness, the book is much more than just a boundary treatise, and provides a truly remarkable synthesis of the vast literature on temperament, from an authoritative overview of its history, to a consummately readable and sophisticated integration of current science, to a thorough elucidation of the relationship of temperament to brain, genes, environment, and psychiatric disorders, to ingenious applications to clinical care and the guiding of parents. Here, the babies are separated from the bathwater, icons of prior research are gently challenged (when necessary), and Rettew has channeled his career-long pursuit of the concepts surrounding temperament into a fascinating, comprehensive, and, most of all, clear and sensible working model that will be of enormous value to clinicians, scientists, parents, and all those who are interested in the development of children.

Rettew acknowledges that many of the concepts and conclusions are best construed as working hypotheses that require further investigation, and that the recommendations he makes in the sections on practical applications range from being well supported to being substantially in need of better-controlled studies. It is these unbiased acknowledgments throughout the book, superimposed on clear thinking about what is known and what remains to be known, and the scholarly synthesis of all of the existing literature into a practical (and testable!) working model, that sets this volume apart. It is encyclopedic in that it is inclusive of the most important theories and scientific advances of the field, focused in that it clarifies the domain of temperament and its complex relationship with psychiatric disorders, innovative in that it elucidates how temperament represents a critical interface among genes, brain, and behavior, and relevant to any reader who is interested in what makes different children different.

Beautifully written in a style that is amazingly enjoyable to read, with tables and summaries that students and scientists alike will find indispensible, this is a major compilation that should anchor all future exploration of temperament, and will help illuminate the path forward for work in this field for years to come.