Abstract
Much research on the quality of child care reveals it-in the case of low-quality child care-to be related to poorer child functioning, net of confounding factors, perhaps especially in the case of cognitive-linguistic performance. Recent work using data from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (USA) makes clear that when children's early negative emotionality/difficult temperament is taken into account, it also predicts externalizing problems reported by teachers through the primary school years. More negatively emotional infants are more affected-for better and for worse-by child care quality than less difficult ones, such that the latter appear unaffected by it but the former benefit from good quality care and are adversely affected by poor quality care. Here we determine whether the same is true when children are restudied in adolescence and the focus is their own reports of externalizing problems, impulsivity and risk taking. Results prove more consistent with a diathesis-stress model of environmental action than a differential-susceptibility-relatedone, in that 15-year-olds who were highly negative as infants report more externalizing behavior (but not risk taking or impulsivity) if they experienced low-quality child care, but not fewer problems if they experienced high-quality care relative to their counterparts with less difficult temperaments in infancy. Results are discussed in relation to physiological stress, with possible explanations offered as to why the predictive nature of child care experience might change over time.