The NICHD Study of Early Child Care and Youth Development began with children born at 10 U.S. hospitals. During infancy, the children were assessed with observations of mother-child interactions, interviews with mothers, and rating forms completed by mothers. For children who received nonmaternal child care, the quality of the care was assessed by observers who rated caregiver-child interactions in the primary childcare arrangements at ages 6, 15, 24, 36, and 54 months.
Although previous studies have reported associations between childcare quality and behavioral/emotional problems among children in general, Pluess and Belsky (2009) tested the hypothesis that childcare quality might have much bigger effects on children with difficult temperaments than on children who did not display the negative emotionality characterizing difficult temperaments. Ns ranged from 761 to 915 for various measures. Among children classified as having difficult temperaments (i.e., being high on negative emotionality), it was found that those receiving low quality childcare had significantly higher Total Problems scores on ASEBA Caregiver-Teacher Report Forms (C-TRFs) completed by caregivers at 54 months than children receiving high quality care. The same was true for teachers’ ASEBA ratings when the children were in kindergarten. By contrast, no significant associations were found between teachers’ ASEBA ratings and childcare quality for children who were low in negative emotionality. In other words, there was a strong interaction between the effects of difficult temperament and the quality of childcare on ASEBA problem scores, such that children who were high on negative emotionality were strongly affected by the quality of childcare, whereas the quality of childcare did not affect ASEBA problem scores obtained by children who were low on negative emotionality. In fact, children who were high on negative emotionality but received good childcare actually had lower ASEBA problem scores than children who were low on negative emotionality, whether they received good or poor child care. The authors therefore concluded “it is not just that negatively-emotional infants are more at risk of succumbing to the adverse effects of problematic rearing environments, but that they also reap a greater benefit from supportive family and childcare environments” (p. 401).
Reference: Pluess, M., & Belsky, J. (2009). Differential susceptibility to rearing experience: the case of childcare. Journal of Child Psychology and Psychiatry, 50, 396-404.