A working paper from the Curry School of Education at the University of Virginia investigated the persistence of effects of early childhood interventions and asked whether these effects fade systematically. The study found that “by the end of kindergarten [Year 1] children who attended preschool are no longer outperforming on measures of reading and math relative to their peers.”
The study used two datasets: a 2010 kindergarten cohort, which the authors used to explore the relationship between attending preschool and cognitive and behavioural skills at school entry and through first grade; and a 1998 kindergarten cohort, which enabled comparisons of the effects of preschool attendance in 1998 and 2010.
In 1998 and 2010, children who attended preschool showed benefits in cognitive skills when they started school. Analysis of the 1998 cohort showed that these benefits persisted through kindergarten and first grade (equivalent to the end of Key Stage 1). Analysis of the 2010 cohort showed that, despite their advantage when first attending kindergarten, preschoolers had no cognitive advantage over other children by the end of the kindergarten year.
The fade-out effect was similar whether children attended preschool full-time or part-time and irrespective of kindergarten class size, length of the kindergarten day, and other quality measures.
The results are similar to a recent report in Best Evidence in Brief, which compared children in England who went to preschool in the late 1990s with those from 2005 onwards. Again, the older children’s benefits persisted, whereas the younger ones’ faded.
Source: Working Paper: Preschool Fade Out (2015), Curry School of Education