CHAPEL HILL - What happens to children at home before starting school has about twice the educational impact of day care, a major new study concludes. But the influence of day care still is strong, and the quality of that care makes a significant difference in children's readiness for school, the research shows.
The study, conducted at the University of North Carolina at Chapel Hill and nine other U.S. centers, evaluated the effect of day care on 1,364 children. Early education experts consider it the largest and most carefully controlled research of its kind.
"Because of major changes in the U.S. work force, there's been a lot of concern over the past decade about the influence of child care on very young children," said Dr. Martha Cox, senior investigator at UNC-CH's Frank Porter Graham Child Development Center and a principal investigator. "Unlike in the past, now more than half of women with children under age 1 are in the work force. Our findings demonstrate clearly that better quality care before the school years tends to prepare children better to succeed in school later on."
The National Institute of Child Health and Human Development funded and helped design the study, which was scheduled for presentation Saturday (April 17) at the biennial meeting of the Society for Research in Child Development in Albuquerque, N.M.
Besides Cox, UNC-CH researchers who participated in the investigation were Drs. Margaret Burchinal and Donna Bryant, both of the Graham center.
Researchers followed children in the study group from birth, observing interactions both at home with mothers and at day-care centers with staff. They also evaluated youngsters with various sophisticated tests of language and mental development and assessed the quality of their homes and care centers.
Most of the children, who are from racially and socially diverse families, are in the second grade now and will be followed at least until age 10. They were assessed at ages 6, 15, 24 and 36 months.
"We found that quality child care matters, even when you take into account other family and child variables such as income and education of the parents," Cox said. "Children consistently performed better on measures of thinking and language development if they were in good day care than if they were in lower-quality care.
"That was especially true in settings in which caregivers provided more language stimulation and more involved care," she said. "Mothers and children also interacted in more positive ways with each other when the children were in better-quality day care."
As a group, youngsters who experienced poorer care scored lower on the tests. In such centers or private homes, staff did not consistently provide good language stimulation -- such as asking questions and responding to sounds infants and toddlers made.
"Differences we observed were statistically significant over and above effects of the home environment which, as expected, we found were especially strong," Cox said. "This is important for people to know because intellectual and language skills in the early years are the building blocks for school readiness, academic success and self-esteem."
Among objective findings was that, after controlling for various outside influences, 57 percent of children in high-quality care were average or above on a measure of school readiness, Burchinal said. Only 43 percent of subjects in low-quality care, however, were average or above in school readiness.
Another finding was that the quality of out-of-home care seemed to have little impact on the children's social behavior, she said. In other words, researchers could not distinguish among groups of children based on behavior and how high their centers rated in quality.
"These analyses are unique and helpful," Bryant said. "They attempt to put in perspective the degree of importance of the effects of quality child care on children's development."
Some skeptics have acknowledged the statistically significant effect of child care quality but said the effect was not enough to justify the extra cost of ensuring it, she said.
"These new analyses show that child care quality is half as important as family factors, and most people understand that family predictors are extremely important in children's development," Bryant said. "So an effect of half that size -- which is what we see with child care quality -- is indeed meaningful."
The researcher said she wished people would not misrepresent the statistics, and she offered an analogy.
"Lots of men take an aspirin a day based on studies showing a small but significant effect of aspirin on lower rates of heart attack," she said. "The effect of quality in child care is stronger than this effect, yet some people belittle quality, and say it's not important. I guess it depends on what you value."
Besides UNC-CH, which follows 130 children, other data collection centers are located at the universities of Arkansas at Little Rock, California at Irvine, Kansas, New Hampshire, Pittsburgh, Virginia, Washington at Seattle, Wisconsin, and Temple University. Research Triangle Institute staff in North Carolina's Research Triangle Park also participate in the project.
Note: Cox can be reached at 505-247-3344 at the Doubletree Inn in Albuquerque and at 919-966-3509 in Chapel Hill following the meeting.