November 7, 1999
The National Institute of Child Health and Human Development (NICHD) Study of Early Child Care has established that there is no consistent relation between the hours infants and toddlers spend in child care and these children's cognitive, linguistic or social development. In a just-published analysis about mother-child interaction, the study showed that the number of hours infants and toddlers spent in child care was modestly linked to the sensitivity of the mother to her child, as well as to the engagement of the child with the mother in play. This link is sufficiently small so that it can be detected only under conditions in which other predictors of the quality of mother-child interaction are equivalent or are accounted for statistically. The findings appear in the November issue of Developmental Psychology.
The investigators found a modest link between quality of child care and maternal sensitivity, meaning that the better the quality of child care the higher the level of maternal sensitivity. This finding is similar to earlier findings from the same study, showing that higher quality of care is associated with more favorable consequences than lower quality of care. For example, when child care providers talk to children, encourage them to ask questions, respond to children's questions, read to them, challenge them to attend to others' feelings, and to different ways of thinking--children's language abilities and thinking skills are better than under conditions that are less enriched.
In the just-published article the authors found that the results for child care hours and child care quality were not influenced by whether the child was in one form of child care or another.
Both "maternal sensitivity" and "child engagement" describe behaviors that were observed and rated by the staff of the NICHD Study of Early Child Care. Maternal sensitivity refers to how attuned a mother is to the child's wants and needs; child engagement refers to how connected or involved a child appeared to be when relating to his or her mother.
This link between increased time a child spent in nonmaternal care and decreased quality of the mother-child interaction is smaller than the link between the higher level of the mother's education and increased sensitivity of the mother to her child during mother-child interaction. Moreover, the link between time spent in child care and mother-child interaction is equivalent to the link between maternal depression and maternal sensitivity.
Such predictors of the quality of mother-child interaction include family income, maternal education, maternal depression, and mothers' marital status (or the status of having a partner). When families are not similar in terms of these other predictors of the quality of mother-child interaction, the link between hours spent in child care and mother-child interaction can be difficult to detect.
Previous studies on whether the amount of time children spend in child care affected interactions with their mothers had conflicting results. Most of the earlier studies observed only a small number of children, measured the behavior of only one age group, and failed to include children with a very small number of hours in nonmaternal care.
The NICHD Study of Early Child Care enrolled just over 1,300 children at birth at 10 research sites throughout the United States. Children participating in the study were placed in a variety of child care arrangements, ranging from the most informal (care with relatives) to the most formal (center care). The study is being conducted by investigators at the NICHD and at 14 universities around the country. Although the study was not designed to be nationally representative, the average income of study families was similar to the average national household income. The percentage of ethnic minorities participating in the study was similar to the percentage of minorities in the nation as a whole
Mother and child interactions were videotaped in 10-15 minutes sessions when the children were 6, 15, 24, and 36 months of age for almost a total of one hour for each of the nearly 1,300 children for whom the authors had complete information. The quality of the interaction between the mother and her child was assessed in terms of the mother's sensitivity to her child and in terms of the child's engagement with his or her mother during the joint play sessions. Mothers were rated in terms of their sensitivity to the child when the child was not distressed. Observers rated the degree of sensitivity of the mother, the degree of her intrusiveness, and the degree of positive regard or respect she showed toward the child. Child engagement and positive mood during mother-child interaction were also rated.
Because the child care experience is not independent of children's family background, the researchers also studied the family influences on the quality of mother-child interaction. The researchers sought to determine to what extent one can detect links between child care experiences (amount and quality) and the quality of mother-child interaction. They were looking for links that emerge after controlling for or taking into account the associations between family characteristics and mother-child interaction. Family characteristics examined included the mother's marital or partnered status, maternal depression, and maternal anxiety over separating from her child when the child is in child care.
The NICHD Study of Early Child Care is an ongoing study that has followed the children through first grade and is now embarking on their evaluation in third grade. Although the association between hours and quality of child care and mother-child interaction in the first three years of life is modest the authors plan to examine the long-term consequences of the findings.
"The ultimate long-term impact of such modest effects on children's functioning remains to be determined as these children are followed through their early elementary school years," the authors wrote.
The NICHD is one of the Institutes comprising the National Institutes of Health, the Federal government's premier biomedical research agency. NICHD supports and conducts research on the reproductive, neurobiological, developmental, and behavioral processes that determine and maintain the health of children, adults, families, and populations. The NICHD website, http://www.nichd.nih.gov/, contains additional information about the Institute and its mission.
More information about the NICHD Study of Early Child Care is available at http://www.nichd.nih.gov/publications/. News releases on the study's previous findings may be found at http://www.nichd.nih.gov/news/releases/.
This study is directed by a Steering Committee and supported by NICHD through a cooperative agreement that calls for scientific collaboration between the grantees and NICHD staff. The participating investigators in this study are listed in alphabetical order, along with their contact information.