As cities like Seattle consider substantially expanding their public preschool programs, officials have turned to scientific research to help steer the decision-making process. But it’s important to remember that evidence for positive effects of pre-kindergarten comes primarily from studies of preschools that may not be very applicable to large-scale programs today.
One highly referenced study of preschool effectiveness, the Abecedarian Project, enrolled four cohorts of 14 infants from low-income homes between 1972 and 1977. The intervention began when infants were 6 weeks of age and lasted through age 5, when the children began kindergarten. I was part of the research team from 1974 until 1984.
The concerns of the 1970s are not those of today. Care for infants in groups was rare, and possible health problems were a major concern. As a consequence, Abecedarian infant and toddler classrooms were on the same floor as two pediatricians and a nurse practitioner who provided care to the participants. Interestingly, a recent Science magazine article presented long health benefits into adulthood for those who had participated in Abecedarian.
Another aspect that makes scaling Abecedarian difficult is that it operated nine hours a day, 12 months a year, and provided extensive services to the children and families involved. No programs being proposed today can match this level of intensity.
The focus of Abecedarian was the prevention of mild intellectual disabilities. Its funding came from the National Institutes of Health, and a primary outcome of interest was intelligence measured by IQ scores. Focusing on IQ malleability was not unique to Abecedarian. Head Start, begun just seven years earlier, also had a focus on increasing children’s intelligence. Another widely touted program, the Perry Preschool Project, implemented in 1962, began with a focus on preventing children’s need for special education.
The focus on IQ has consequences. All of these early programs were guided by the prevailing view at the time that a generally enriched environment early in life would lead to gains in intelligence. As a result, the curricula used by all had a rather non-specific enrichment focus.
Although it is true that children from poor families tend to be less successful in school — the achievement gap is real and growing — what critical early skills cause this gap have not been established. The earlier studies focused on general enrichment provide little guidance for the construction of new programs.
On the other hand, both Abecedarian and Perry have provided invaluable longitudinal data showing that early experiences are linked to later highly valued societal outcomes. Outcomes such employment, wages, delayed pregnancies and even lower rates of incarceration, in some instances, have been found for children who participated in these programs. But there are no well-controlled studies of typical public pre-K programs with longitudinal follow-up that would reveal whether such programs produce these same long-term effects.
What Abecedarian and Perry should do is inspire us. Although we cannot replicate these experiments, we can recognize the importance of providing positive early experiences for children and the value of examining long-term outcomes to determine our success. Great progress has also been made in understanding how children learn in the decades since Abecedarian and Perry. Merging the current developmental and cognitive research with the insights of early childhood educators is what is needed now to create successful new preschool programs.
Dale C. Farran is a professor in the departments of Teaching and Learning, and Psychology and Human Development at Vanderbilt University in Nashville, Tenn.