Why Do Only Some Institutionalized Children Become Indiscriminately Friendly? Insights From the Study of Williams Syndrome Isabel Soares, 1 Jay Belsky, 2,3,4 Ana R. Mesquita, 1 Ana Os orio, 1 and Adriana Sampaio 1 1 University of Minho, 2 University of California, Davis, 3 King Abdulaziz University, and 4 Birkbeck University of London ABSTRACT—Why do some institutionalized children develop indiscriminate behavior (IB) while others do not? Consid- ering children with Williams syndrome (WS) may provide an answer because IB has been observed routinely among individuals with this rare genetic neurodevelopmental dis- order. By conceiving WS as a natural genetic model that mimics the indiscriminate phenotype and, more impor- tantly, is associated with the deletion of genes in a specific region, we propose an integrative conceptual framework that underscores the dynamic developmental interplay between genes, endophenotypes, and environment. In this article, we consider the etiology of IB among institutional- ized children, which emphasizes environmental factors, followed by the effect of such behavior on WS children’s hypersociability, which highlights the crosstalk between genes and neuropsychological features in programming their distinctive social-emotional and behavioral pheno- type. We propose new hypotheses regarding the etiopa- thogeny of IBs in institutionalized children, particularly the prediction of specific Gene 3 Environment interactions. KEYWORDS—indiscriminate behavior; institutionalized chil- dren; Williams syndrome For most infants growing up under adequate rearing conditions, a developmental shift occurs in the last quarter of the first year from a general, positive social orientation toward others to a more focused, discriminating preference for particular signifi- cant others. In contrast, formerly and currently institutionalized children can show persistent indiscriminate behavior (IB), approaching unfamiliar adults without reticence, wandering away from their caregivers without checking back, and behaving affectionately toward familiar and unfamiliar adults (Bruce, Tarullo, & Gunnar, 2009; Oliveira et al., 2012; Rutter et al., 2007; Smyke, Dumitrescu, & Zeanah, 2002). In the last four decades, several research teams have chron- icled such atypical behaviors in currently and formerly institu- tionalized children, often guided by insights from attachment theory. These teams consistently report that, in contrast to children living with their families, those living in institu- tions (and thus being cared for in a traditional—and very neglectful—manner) often display overfriendly attention and comfort seeking and affectionate behavior toward unfamiliar people (Smyke et al., 2002). More recent reports indicate that even after several years of placement in adoptive families, a significant number of children who spent their early years in depriving orphanages continue to show mild to high levels of IB (Rutter et al., 2007). Furthermore, the presence of IB does not seem to be restricted to formerly and currently institutionalized children; significant levels have been reported in high-risk families, where neglect is also prevalent (Lyons-Ruth, Bureau, Riley, & Atlas-Corbett, 2009). Isabel Soares, Department of Applied Psychology, School of Psychology, University of Minho, Braga, Portugal; Jay Belsky, Uni- versity of California, Davis, USA; King Abdulaziz University, Saudi Arabia; Birkbeck University of London, UK; Ana R. Mesquita, Ana Os orio, and Adriana Sampaio, Neuropsychophysiology Lab, CIPsi, School of Psychology, University of Minho, Braga, Portugal. The authors acknowledge the support of Carla Martins in the prep- aration of the manuscript. This review was supported by grants from Bial Foundation (Ref.13/06) and from the Portuguese Foundation for Science and Technology—PTDC/PSI-PCL/116897/2010; PTDC/PSI PCL/115316/2009; PTDC/PSI-PCL/101506/2008. Correspondence concerning this article should be addressed to Isabel Soares, School of Psychology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; e-mail: isoares@psi.uminho.pt. © 2013 The Authors Child Development Perspectives © 2013 The Society for Research in Child Development DOI: 10.1111/cdep.12036 Volume 0, Number 0, 2013, Pages 1–6 CHILD DEVELOPMENT PERSPECTIVES