Sex Differences in Antisocial Behaviour: Conduct Disorder, Delinquency and Violence in the Dunedin Longitudinal Study. By T. Moffitt, A. Caspi, M. Rutter and P. Silva. (Pp. 278; £14.95/$21.95.) Cambridge University Press: Cambridge. 2001.

Despite significant advances over the last two decades in our understanding of the origins and development of antisocial behaviour (Patterson & Yourger, 1993; Offord, et al. 1996; Farrington, 1998; LeBlanc & Loeber, 1998), several questions have continued to plague the field. For example, what would a comprehensive longitudinal picture of sex differences in antisocial behaviour look like and what would it reveal about the aetiology, continuities and discontinuities of antisocial behaviour? Should sex differences in the amount of antisocial behaviour be taken as evidence that males and females experience different developmental patterns? How should research and clinical communities deal with the raised prevalence figures of conduct disorder among boys? Should the diagnostic criteria for conduct disorder in girls be relaxed? This book by four internationally respected authors describes an integrated and novel approach to the above questions. Essentially, the book addresses an anomaly that has arisen from two facts about antisocial behaviour which, when considered together, distinguish antisocial behaviour from depression, anxiety, ADHD, autism and other disorders of childhood, namely that there is a male preponderance in antisocial behaviour, and that there is a large increase in antisocial behaviour during adolescence. In addressing this anomaly in a systematic way by investigating age-related sex differences in antisocial behaviour, the fundamental causes of such behaviour are described in a way that has not previously been done. The book comes to a powerful conclusion that will no doubt influence future directions in the field, namely that the more severe, early-onset presentation of antisocial behaviour that is typical of only 5% of males is associated with neuro-cogntitive features with probable strong genetic and biological influences. By contrast, females ’ antisocial involvement tends to fluctuate more according to circumstances and therefore is more influenced by social factors, notably the socialization influences by male peers. These influences are particularly relevant during middle adolescence. The book’s conclusion is based on the data of one long-term longitudinal study of a contemporary representative birth cohort of 1000 males and females born 1972–1973 – the Dunedin Multidisciplinary Health and Development Study. Subjects were followed up for nine assessments spanning a period from 3–21 years of age, thereby covering the peak ages for the emergence of antisocial behaviour. Data sources were wide and in the tradition of longitudinal studies included dimensional measures like parent, teacher and self-report. In addition, observer ratings, official police and court records, peer information reports and partners reports were used. These measures produced two methods of quantifying behaviour: a dimensional scale and a categorical diagnosis of conduct disorder. In demonstrating the comparison in findings between these two methods, important methodological lessons are taught to the young researcher and}or student who read this book. Chapter 1 provides an excellent guide to the rest of the book in that it succinctly describes the main hypotheses and aims of the book. It then sets out to describe the content of each chapter in a clear and logical manner. In doing so the argument on which the book is based unfolds clearly in the first chapter, and the reader is left with a good sense of study’s main conclusions by the time (s)he starts to fill in the details by reading the rest of the book. Chapter 2 addresses the study design and provides an informative overview of the New Zealand research setting. Chapters 3–5 bring together methodologies from developmental psychology, social psychology