Early Experience and Early Intervention for Children ‘‘at Risk’’for Developmental Delay and Mental Retardation

THE ORIGINS OF EARLY INTERVENTION RESEARCH FOR ‘‘AT RISK’’ INFANTS AND CHILDREN In 1801, a French surgeon, Itard, began an educational intervention with an 11 year old boy that has since become classic [Itard, 1932]. From his work with the child he found running naked and wild in a forest (‘‘the savage of Aveyron’’) emerged hope, as well as understanding, about the role of early experience and the benefits of systematic instruction. Over the course of five years, the boy showed progress, even after the extreme conditions of his early life. In modern neurobiological terms, this case study indicated some cortical neuroplasticity well into middle childhood. Yet there remained many severe deficits and gaps in behavioral functioning that could not be overcome in the areas of language, social–emotional regulation, and reasoning. These observations were consistent with the view that certain types of early experience were essential for the emergence of higher order intellectual functioning. That is, later provision of comparable experiences or even highly individualized, intensive education could not adequately compensate for the developmental toll associated with extreme neglect and lack of early human stimulation and interaction. A series of landmark studies of infants and young children in orphanages and institutions, begun in the 1930s and 1940s, raised grave concern about the serious and lasting harm caused by the loss of a mother and subsequent care in a group setting. The work of Bowlby, Dennis, Goldfarb, Skeels, Skodak, and Spitz, among others, revealed that the conditions children faced in these institutions were horribly inadequate compared to the love, stimulation, and stability of a good family [see review by S. Ramey and Sackett, in press]. This research set the stage for vigorous scientific inquiry that sought to identify precisely what young children need—early in life—to ensure healthy growth and development. The efforts included carefully controlled experiments using animal models which systematically varied the type and timing of early experiences, as reviewed by Sackett et al. [1999]. At first, these experiments concentrated on documenting the effects of social and sensory deprivation, although the paradigm subsequently was extended to study the consequences of early environmental enrichment. Collectively, the results provide compelling evidence that early experience matters, a lot; and in the extreme, deprivation can produce functional mental retardation and aberrant social and emotional behavior in animals born healthy and with good genetic endowment. A second line of research focused on understanding variation in young children’s responses to non-optimal settings and the extent to which environmental ‘‘habilitation’’ could reverse or minimize the negative effects of institutionalization or other forms of early deprivation [cf. Landesman-Dwyer and Butterfield, 1983; Landesman and Butterfield, 1987]. This work clearly confirmed a fundamental principle of social ecology, known as Person X Environment interaction: that not all individuals respond similarly to the same environment [e.g., Bronfenbrenner, 1979; Landesman and Ramey, 1989]. Based on this principle, the role of actual experience at the individual level, rather than mere exposure to environmental conditions, was directly implicated in mediating the effects of early deprivation. The factors hypothesized to contribute to the observed differences in children’s responses to similar environments (e.g., orphanages and institutions) were biological and genetic differences (including gender), age when deprivation occurred, life history prior to deprivation, duration of exposure, and the child’s own behavioral repertoire, which often serves to elicit different degrees of positive caregiving and social interactions from others. A third and independent line of inquiry, also grounded in the landmark studies of orphanages and institutions, was a pro-active effort begun in the 1960s to prevent the developmental toll observed all too frequently among children from extremely poor families. These efforts to provide early educational enrichment to infants and young children from low resource families were also fueled by scientific findings from the fields of child development, mental retardation, and the new