Indiscriminate social behaviour: Environmental, neural and genetic approaches to understanding the effects of institutionalisation in preschool children

Even though early institutionalisation is known to compromise children’s development, limits remain in the understanding of how and why some children develop a pattern of indiscriminate social behaviour (IB) and others do not. This thesis aims to address that question, by assessing IB using both the caregiver’s report and observations, and by exploring multi-level influences. An introductory background (Chapter 1) reviews the literature on attachment disturbances and IB, and discusses current perspectives on their conceptualisation and what is known about etiological factors. This is followed by a description of the methods employed in various studies of this thesis (Chapter 2). The empirical studies investigate environmental (Chapter 3), neural (Chapters 5 and 6), and genetic (Chapter 7) influences on IB in Portuguese institutionalised children. Firstly, broad indices of adjustment are explored in relation to explanatory variables of the quality of care (Chapter 3). Greater caregiver sensitivity predicted reduced IB, but not other behavioural outcomes, in support of the role of the quality of micro-caregiving in explaining IB and IB as an independent construct. Before introducing the empirical studies of neural functioning, a systematic literature search summarises the findings of electrophysiological studies conducted with institutionalised children (Chapter 4). Next, findings of Event-Related-Potentials (ERPs) recorded while children visualised the face of their caregiver and a stranger are reported. In the first level of analysis, institutionalised children are compared to a group of family-reared children (Chapter 5). Consistent with the literature, institutionalised children showed reduced amplitudes in occipital components. In the second level of analysis, two subgroups of the institutionalised children are compared: those who presented IB and those who did not (Chapter 6). Children with IB showed reduced amplitudes in occipital components, as well as alterations in the processing of the familiar versus unfamiliar face, suggesting that part of the effects attributable to institutionalisation are particularly shown by children who developed IB. Genetic influences on IB are explored in the last empirical study (Chapter 7), by testing the association between variations in one polymorphism of the oxytocin receptor gene and the presence of IB. Carriers of the A allele showed increased levels of IB. The final Chapter 8 integrates these results and discusses their implications for the understanding of IB and the development of children in institutional care, alongside future directions for investigation and policy