Documented efforts to enhance the development of children, especially to remediate the consequences of deprivation, have taken place since the early nineteenth century, when researchers learned that certain types of early experience were essential for the emergence of high intellectual functioning. More recently, studies of children in orphanages in the 1950s and 1960s initiated the investigation of what young children need to ensure healthy growth and development. This paper traces subsequent attempts to identify factors contributing to impaired development and measures to ameliorate them in several early intervention programs. The analysis of data gained from these programs indicate that the rates of mild mental retardation associated with extreme poverty can be substantially reduced by intensive programs of significant duration and that additional social benefits will accrue as a result. Research following the orphanage studies took three tracks. One track conducted behavioral experiments on animals and demonstrated that deprivation can produce mental retardation and aberrant social and emotional behavior in animals. A second line of research sought to understand variation in young children’s responses to non-optimal settings and the extent to which improvements in the environment could reverse or minimize negative effects of deprivation. Factors hypothesized to contribute to the variation included biological, genetic, gender, timing and duration of deprivation, the life history of the child prior to deprivation, and the child’s own behavioral repertoire, which may serve to elicit different caregiving and social interactions. The third track of research showed that (a) the rates of mild mental retardation were markedly elevated among very poor families, (b) the quality of a child’s home environment – including the responsivity and sensitivity of the mother to her child, the amount and level of language stimulation, direct teaching, and parenting styles – correlated with the child’s intellectual and problem solving abilities, and (c) that very young infants could learn, that they could learn in many different ways, and that early learning experiences directly affected infants’ responses to subsequent learning opportunities. As a result of these research findings, enrichment programs were initiated to prevent developmental and mental retardation among extremely poor families. The first attempts at enrichment took place in highly-controlled, university-based preschool centers; these compensatory programs differed considerably in duration, timing, and intensity. They provided interesting toys, books, music, and games; responsive educated care givers; a safe environment, nutritious meals, regular rest and vigorous activity; and congnitively rich environment where language and thinking skills were encouraged. The substantive content of what was offered was sound and often proved successful.
We analyzed the efficacy of eleven early intervention programs for children “at risk” and supplied the authoritative study of early intervention programs. The consortium derived two major conclusions: (a) reaffirmation that the programs did produce significant gains in intellectual and conginitive performance of participating children, and (b) the magnitude of gains, as indexed by IQ, scores peeked at the end of intervention and for three or four years thereafter, then declined over time, the often-noted “fade out effect.” Because of the attention generated by the IQ decline, the longitudinal study’s positive conclusions about long-lasting effects of early education programs for children from low-income families – school competence, developed abilities, attitudes and values, and impact on the family – were largely ignored. Continued longitudinal inquiry and new intervention studies have provided additional data for better understanding the development in children who receive different types and amounts of early intervention. Five studies focused on groups of children at high risk for mental retardation. All of these intensive, multi-pronged programs involved random assignment of children to intervention or control groups; and in each program, intervention continued for a minimum of one year prior to age 4.
The five major programs all demonstrated significant and clinically meaningful IQ increases and corresponding decreased rates of mental retardation. For four of the programs, multiple benefits persisted until middle school or later, although IQ differences between groups declined or disappeared. In contrast to the decline in differences in IQ, more substantial benefits appeared in terms of everyday performance indicators: decreased rates of grade retention special education placement, improved school achievement. The study showed benefits continuing into adulthood, including economic self-sufficiency, educational attainment, decreased criminal activity. The one study that did not show long-term benefits selected children on the presumed biologic risk factors of premature and low-weight birth and concluded intervention by 34 months of age. All other programs continued until children entered school or beyond and selected children according to demographic risk characteristics (especially maternal characteristics), or according to significant developmental delays apparent by age 4.
In a social ecological model of development refined over the past two decades, the authors posit that a child’s competence is determined by a multitude of forces, including intergenerational factors, biological factors, parental competencies, and community social and cultural norms and practices. In this model, the important influences on intellectual competency are the direct transactions a child has with the immediate environment. Thus early intervention programs that provide more intensive educational services, that start earlier and last longer, and that target the child’s everyday experiences are hypothesized to be the most beneficial. This hypothesis finds support in a recent analysis which agree on the causal mechanisms of development. However, children in these programs still performed below national norms and still needed additional support. Children from high risk families clearly benefited from compensatory experiences, although these did not entirely eliminate all risks as children continued to live with their natural families and attended public schools in their locale.
Analyses confirm a strong association between low levels of maternal education and/or low maternal IQ and the magnitude of benefits in children. The home environment exerted a powerful influence on the development of children among children at greatest risk, those with very low IQ mothers. Premature children with heavier low birth weight from families with the greatest social and economic risks benefited most from early intervention. To date, none of the large scale authorized programs for children living in poverty have produced the same types of benefits that smaller scale studies have. Several factors may account for this apparent reduction of benefits. The smaller scale programs provided far more intensive educational supports to a greater proportion of enrolled children than large scale programs. Also, enrollment in federal programs is based on poverty income, and children in the programs are not at the high levels of risk for developmental or mental retardation or for special education placement as were the children in the small scale programs. However, the number of children at high risk of mild mental retardation associated with sociodemographic factors, the most prevalent form, can be reduced by 49% or more with high quality, intensive, multi-year, multi-pronged, targeted intervention. The cost benefits of such preventative programs would show up in reduced numbers of students entering special education, reduced grade retention, reduced remedial summer programs, reduced criminality, and reduce welfare enrollment. Given the increasing evidence that brain development is affected by early and cumulative life experiences and the positive results of the early intervention for high risk children, there is ample support to justify systematic prevention efforts. Without this, children from very low income families are likely to continue to fulfill their intergenerational prognosis of sub-average intellectual performance and marginal social and economic existence. Challenges to early childhood developmental programs include a lack of advocacy and the jeopardizing of existing home-visiting programs, but the two greatest obstacles seem to be informing opinion leaders and policy makers about the benefits and the general resistance to developing a new large scale program in the light of many that have had disappointing results. The situation calls for a comprehensive analysis of such large scale programs so that current investments may be redirected. With such an analysis in hand, scientific facts and political realities may be effectively integrated.