As a group, children in day care learn to think and talk just as well as those cared for by their mothers, a long-term national study has found.
The study, being released today by the National Institute of Child Health and Human Development, did find, however, that the quality of care matters: Children whose caregivers respond and speak frequently to them perform better on thinking and language tests than those in settings where they have less verbal interaction.
The study also confirmed an earlier finding by the same group of researchers that day care has far less of an impact on children than do their circumstances at home, including economic resources, their mother’s psychological health and their own temperaments.
While many of the findings should be reassuring to working parents, the study did indicate that placing a very young child in day care for many hours each week has a small negative impact on the mother-child relationship. Researchers found that the more hours children 6 months and younger spend in day care, the more likely their mothers are to show some insensitivity or negative interaction with them.
That could be the result, researchers speculated, of parental stress or weaker bonding that occurs when families try to juggle work and very young children.
The findings, which are being presented at a conference in Washington today, represent the second phase of a massive ongoing study involving 10 teams of researchers who are following 1,300 families across the country from the birth of their children through age 7.
The study, which is larger and more detailed than any previous research on the subject, is designed to answer a question of intense concern to American families: Is day care harmful to the social and intellectual development of children?
That question is critical because half of all women with children younger than age 1 are working, and most of those women return to work before their children are 6 months old.
Many very young children spend a substantial part of their days in the care of someone other than their parents. At the age of 15 months, 70 percent of the children in day care were there at least 30 hours a week, the research found.
The new study underscores the conclusion of a growing body of research showing that one of the most important positive influences in a child’s early development is a rich and stimulating environment, whether provided by a parent, a day care provider or another family member.
Unlike previous child care studies, which were limited to certain types of care or only parts of the country, the NICHD study began with a pool of nearly 9,000 families, then narrowed the group down to a diverse selection based on economic status, single-parenthood, education of the mother and numerous other characteristics.
The diversity of the families, researchers say, made for a wide range of child care arrangements, including day care centers, nannies, fathers, relatives and care in the home of another family.
The first phase of research, released a year ago, concluded that day care of itself did not harm children’s emotional attachment to their mothers.
The second phase of the research focused on the behavior of mothers toward their children as well as the impact of child care on cognitive and language development. Researchers measured whether the number of hours in care and the quality of care made a difference.
When it came to intellectual skills, it was clear that the number of hours in care did not have an effect, but quality of care did.
“One very important take-home message … is that children in child care are not doing any worse than children not in child care” on cognitive and language skills, said Sarah Friedman, coordinator of the study. “For those children in child care, the better the quality of the care, the better the outcome.”
Specifically, it was the tendency of caregivers to engage children in conversation, respond when children spoke and interact verbally with them that led to the highest scores on thinking and language tests, the study found.
The study did not attempt to categorize what type of child care - provided in centers, by relatives or in another family’s home - was most likely to offer the best quality. It also did not directly compare whether children in poor-quality care developed as well as children cared for by their mothers.
Instead, it compared only children in day care as a group with the group of those under maternal care.
When researchers looked at the second focus of the study - the relationship of mothers to their children - they found that both the quantity and the quality of care had some impact, although it was weaker than the effects found for intellectual development.
The study did find the link between the number of hours children spent in day care when they were very young and less positive interactions with their mothers, which seemed to persist even when the children were 3 years old.
“These aren’t big, powerful, overwhelming effects, but you can pick them up at different ages,” said Jay Belsky, a psychologist at Pennsylvania State University.
Deborah Lowe Vandell, a professor of educational psychology at the University of Wisconsin, said that extended hours in care early in life “may be a real source of stress for mothers, which gets reflected in their behavior.”
At the same time, however, researchers also found that high-quality care, in which caregivers and children have frequent, positive interactions, could help the mother-child relationship.
Researchers evaluated these relationships by observing videotapes of mothers playing with their children and by visiting the families’ homes and watching how the mothers interacted with their children.