Data from the same long-running study (the NICHD Study of Early Child Care and Youth Development), this time involving 1,364 youth (followed since birth), found that teens who had spent the most hours in non-relative child care in their first 4½ years reported a slightly greater tendency toward impulsiveness and risk-taking at 15 than did peers who spent less time in child care (21% were in care for more than 30 hours a week; 24% had had more than one year of care by 4 ½). But it was the quality of child care that made the difference as far as cognitive and academic performance was concerned. Those who had higher quality child care had better results on cognitive and academic assessments at both age 4½ and age 15. High-quality care was characterized by the caregivers' warmth, support, and cognitive stimulation of the children under their care. More than 40% of the children experienced high-quality (17%) or moderately high-quality (24%) care. The findings were consistent across gender and socioeconomic status. Previous research has tended to focus on the effects of child care on disadvantaged children; this one is notable for involving children across society. The study is important not only for pointing to the effects of childcare quality, but for the finding that the effect continues into adolescence.
(2010). Do Effects of Early Child Care Extend to Age 15 Years? Results From the NICHD Study of Early Child Care and Youth Development.
Child Development. 81(3), 737 - 756.