This monograph is concerned with the mid adolescent follow-up of a group of adoptees from Romania and from within the United Kingdom who were first assessed at the age of 4 years (or 6 years in the case of the oldest children). Chapter I provides the background as it applied at the time that the study began, and then goes on to outline the overall research strategy and the measures relevant for the first assessment at age 4 years. It then goes on to summarize, briefly, some of the key findings from the follow-ups undertaken up to the age of 11 years. In the authors' published papers on the age 4-, 6-, and 11-year assessments, they mainly dealt with findings in relation to key outcome variables. In this monograph, they have adopted a different strategy that capitalizes on the unique features of their study. Their study is the only investigation with detailed interview and observation measures, together with psychometric assessments, spanning a 10-year follow-up period. Most especially, their study is unique in having systematic, standardized measurements of key behavioral patterns that seem to be specific to institutional deprivation. Accordingly, the authors have been able to focus on the crucial issue of the extent to which these patterns account for the deficits and problems that have persisted to age 15 years. In order to do that, it was first necessary both to determine which patterns met criteria for specificity to institutional deprivation and to determine their boundaries. This topic is tackled in Chapter III, after outlining the methods and measures in Chapter II. Chapter IV builds on the authors' prospective data over the course of a decade in order to describe the developmental course of the deprivation-specific psychological patterns (DSPs) defined in Chapter III. To facilitate this, the several apparently DSPs are pooled, having noted the major overlap among them. Chapter V considers disturbances of emotion, conduct and peer relations--that is, the three major domains of psychopathology that, up to age 11 years, appeared "not" to follow a DSPs. Chapter VI takes as its starting point the major catch-up found in cognitive functioning following adoption and goes on to ask how far cognitive findings vary according to specific cognitive function and how far cognitive gains up to age 11 have been translated into meaningful educational attainments at age 15-16 years. Chapter VII reevaluates these findings in the light of the age 15 results and examines the physical growth and maturational effects of institutional deprivation. It considers how far the findings differ according to the presence/absence of institutional deprivation-specific features. Chapter VIII reexamines the issue of possible postadoption environmental mediators, paying attention to key methodological challenges. Throughout their study, there has been abundant evidence of heterogeneity in outcome. Chapter IX seeks to pull together the relevant findings with respect to possible biological moderators and mediators. There is reexamination of the apparently protective role of minimal language skills, of genetic influences on environmental susceptibility, of possible effects of social cognitive features, of the role of subnutrition, and of impaired head growth. Finally, Chapter X provides an overview of the findings at age 15, together with the theoretical and practical implications of these findings. (Contains 48 tables and 21 figures.)