Etienne E. Baulieu* The theme of this book, Heterotypical Behaviour in Man and Animals, should be of great interest to physiologists, endocrinolo gists, physicians, and workers in social sciences. Although Heterotypical Sexual Behaviour is a major theme, this volume attempts to display wide interest in reproductive medicine, general physiology, and behaviour in the two sexes. The editors explore the psycho-social dimension, not only of sexuality, but of eroticism which, as recalled by John Money, has its etymological root in the Greek word for love. Being an endocrinologist, who has studied hormone function in terms of synthesis, metabolism, distribution and receptors of these messenger molecules, I would like to recall some data which are basic when considering the overall human machine. It is common knowledge that androgens and oestrogens are formed in both sexes, differences being observed only in concen trations and rhythms of secretion. In the brain of the two sexes, there appear to be the same enzymes which may transform androgens to oestrogens, a process which could explain some aspects of CNS differentiation and activity. Both males and females have androgen and oestrogen receptors, and neural y these receptors appear to be present at the same order of magnitude and distributed according to the same pattern. There is even a similar distribution of receptors for progesterone, the hormone of pregnancy, in the brains of males and females. Therefore, several important pieces of the machinery transmitting sexual information * Laureat of the 1989 Albert Lasker Clinical Medical Research Award."

. Aggression research is in a rapid state of development. The accelerating knowledge of neurotransmitter systems in the brain, their behavioural functions and the development of drugs which may specifically affect systems related to attack and defence is fruitfully combined with studies in which basic ethological observation and quantification techniques are used more routinely. Moreover, much of the experimental effort has finally applied some order to the initial chaos which afflicted the various experimental aggression models used in pharmacological, physiological and ethological research. This highly desirable trend not only leads to a better understanding of the phenomena studied and the terminologies employed, but it increases our awareness of the multiplicity of factors that are important, making it difficult to allow over hasty and simple generalizations. This book is a compilation of studies presented at the International Society for Research on Aggression meeting in Chicago 1986, in which leading investigators were invited to cover aspects of ethopharmacological aggression research in a wide variety of species, including studies on humans. The level to which ethological techniques have been incorporated into the various areas of research differs, as well as the knowledge and understanding of the neurotransmitter and experimental drug action on brain functioning in mammalian species. This naturally results in data which are not always easy to compare or to extrapolate between species but useful indicators are starting to emerge.

An Advanced Study Institute on the Biology of Aggression was held in glorious weather between the twenty-first and thirtieth of July 1980, at the Chateau de Bonas, Gers, France. The Institute was arranged by a scientific organizing committee consisting of Drs. Paul Brain and David Benton of the University College of Swansea, Wales, U.K. This book reflects the papers presented at the A.S.I., and the arrangement of the book parallels the pro gramme. The particular objective was to concentrate on recent research on aggression from the viewpoint of the diverse biological disciplines that have examined the topic. A major theme that emerged was the failure of direct reductionist approaches that look for simple relationships between biological variables and 'aggression'. As may have been predicted, there was also con siderable debate about the definition of the term aggression and its associated positive and negative implications. The organizers would like to express their appreciation to Professor and Madame Simon for their foresight in founding the Association Scientifique Cu1tu e11e et Educative de Bonas and their enthusiasm in designing and converting the Chateau de Bonas to produce a unique conference centre, a venue that greatly facilitated this A.S.I.'s objectives. Greatfu1 thanks are also due to the Faculty who selflessly gave of their time; to Dr."

This volume is the outcome of a NATO Advanced Study Institute on the Ethoexperimental Analysis of Behavior, which was held at II Ciocco in Tuscany, in July, 1988. This particular ASI had an interesting history. In 1980, a NATO ASI on the topic of the Biology of Aggression was held in Bonas, France. This meeting brought together a group of European and American researchers and students from diverse areas, including Psychology, Zoology, Genetics and the like, all of whom were involved or becoming involved in the study of aggression. The Bonas meeting outlined several emerging trends in aggression research, the most prominent of which was an increased emphasis on the behavioral aspects of aggression. This included studying a variety of aggressive behaviors rather than single measures; an interest in what might have been previously considered minutiae, such as the targets for bites or blows and the specifics of movement relationships in dyadic interactions; and a desire to relate the dependent variables of laboratory tests to the typical aggressive behaviors seen for related animals in their natural habitats. This increased attention to natural patterns of aggressive behavior was also very interesting in light of the many findings presented at the Bonas meeting which indicated particular involvement of a number of biological systems in aggression: These findings suggested that aggression constitutes an evolved neurobehavioral system (quite possibly more than one, in fact) representing the activities of a relatively specific biological substrate expressed through a patterned system of behaviors.

This volume is the outcome of a NATO Advanced Study Institute on the Ethoexperimental Analysis of Behavior, which was held at II Ciocco in Tuscany, in July, 1988. This particular ASI had an interesting history. In 1980, a NATO ASI on the topic of the Biology of Aggression was held in Bonas, France. This meeting brought together a group of European and American researchers and students from diverse areas, including Psychology, Zoology, Genetics and the like, all of whom were involved or becoming involved in the study of aggression. The Bonas meeting outlined several emerging trends in aggression research, the most prominent of which was an increased emphasis on the behavioral aspects of aggression. This included studying a variety of aggressive behaviors rather than single measures; an interest in what might have been previously considered minutiae, such as the targets for bites or blows and the specifics of movement relationships in dyadic interactions; and a desire to relate the dependent variables of laboratory tests to the typical aggressive behaviors seen for related animals in their natural habitats. This increased attention to natural patterns of aggressive behavior was also very interesting in light of the many findings presented at the Bonas meeting which indicated particular involvement of a number of biological systems in aggression: These findings suggested that aggression constitutes an evolved neurobehavioral system (quite possibly more than one, in fact) representing the activities of a relatively specific biological substrate expressed through a patterned system of behaviors.