ABSTRACT
More than a decade ago, Brian Sutton-Smith and Ben Rosenberg published a book entitled The sibling (1970). In this book, they summarized the results of research, much of it conducted by the authors themselves, on the effects of birth order and sibling status on personality and intellectual development. By the time the book was written, the accumulated evidence was impressive, but somewhat paradoxically, publication was associated with (if not causally related to) a temporary decrease in the amount of attention paid by researchers to sibling relationships and effects. The publication of the present volume, replete with chapters containing recent findings and the description of ongoing studies, testifies to the current resurgence of interest in sibling relationships and their formative significance. There are, however, several important differences between the research on sibling relationships conducted decades ago and the type of research that is now gaining popularity. These differences involve: a) a shift from the study of effects to the study of formative processes; b) the appreciation of cultural variability and the need to consider inter- and intraspecies diversity and similarity; and c) the growing concern with development across the lifespan, rather than only in childhood. Let us consider each of these issues in turn.
