Child’s Play

right Researchers are learning that it’s not easy to make generalizations about the benefits or drawbacks of child care on young children.

Researchers investigating the effects of child care on young children are learning that it’s not easy to make generalizations about its benefits or drawbacks.

Findings from the federal government’s long-running study of child care, in fact, are often used to back up opposite arguments. A particular focus of debate has been the link, if any, between child care and aggressive behavior in children.

Those who think out-of-home care exposes children to negative influences emphasize the recently published conclusion from the “Study of Early Child Care and Youth Development” that the more time some preschoolers spend in child care, the more likely they are to be aggressive and disobedient in kindergarten.

When the results were first presented at a conference and to the news media two years ago, Kathleen Parker, a conservative columnist for the Orlando Sentinel newspaper in Florida, called the findings “a chilling statement as we wonder what to do about bullies who always seem to surface in news stories about school killings.”

Advocates for improving child-care settings, meanwhile, have highlighted findings from the same study showing that children who spend time in center-based arrangements display stronger cognitive and language skills than those in other types of care.

W. Steven Barnett, the director of the National Institute for Early Education Research, a think tank at Rutgers University in New Brunswick, N.J., is one of the people who have focused on the positive.

“The benefits of preschool can far outweigh the potential risk of behavior problems, and the parents of each child have different factors to weigh in making the child-care decision,” he said in a press release when the findings were published in the July/August 2003 issue of the journal Child Development.

And still others encourage mothers just to cover their ears for fear that the latest statistical tidbit—whether it’s positive or negative—will leave them second- guessing their choices about working or staying home with their children.

But as convincing as any of the arguments seems to be, none answers the real question that the public should be asking about the effects of child care, says Robert C. Pianta, an education professor at the University of Virginia, in Charlottesville, and one of more than 30 investigators in the network conducting the study.

The question—one that papers published by the researchers will soon begin to answer—is who these children become later in life.

“We want to know if there is some lasting legacy of early experience,” Pianta said in a recent interview. “I think people are going to see in the next couple of years the real value of our study as our findings broaden.”

While the underlying theme of how children spent their early years will remain, findings are beginning to emerge on the classroom and out-of- school experiences of the 1,100 children studied—most whom have now completed the elementary grades.

As they have observed the children in school, the researchers have collected data on how they interact with their teachers and their classmates.

“There’s very little observational data on kids in schools,” says Kathleen McCartney, an education professor at Harvard University and one of the researchers on the study, which is sponsored by the National Institute of Child Health and Human Development. “The advantage we have is that we started at birth.”

Papers soon to be published in various journals will show that children’s experiences in school are still “dominated by whole-group instruction and individual seat work,” Pianta says. And just because a child is in a high-quality classroom in 1st grade doesn’t mean he or she will have the same experiences in 3rd grade at the same school, he adds.

Questions are also being asked about whether children from poor families receive less literacy instruction when they enter school, and how the children are affected by their after-school experiences.

The researchers will also continue to follow the issue of behavior.

“We haven’t yet found whether high-quality experiences ameliorate aggressive behaviors,” Pianta says, but he adds that “even when we take into account everything we know about a child’s history, experiences in school do matter.”

While the researchers originally received funding to follow the children through 6th grade, they have submitted a proposal for money to continue studying the children through the end of high school.

It’s then, Pianta hopes, that educators will view their work as a study of childhood, not just child care.

In addition to the debate over whether the press overstates small effects in such studies, the fact that the researchers themselves sometimes have different interpretations of the data has also been a juicy topic for columnists and talk shows.

On a 2001 conference call with reporters, Jay Belsky, a professor at Birkbeck University in London and one of the principal researchers on the study, said the findings suggested that children might be better off if they spent less time in care. But his colleagues pointed out that the behavior problems still fell into a range considered normal for children, and that it was premature to make such a recommendation.

The researchers themselves don’t seem affected by what reporters might portray as a controversy. In fact, McCartney says it’s good that the scholars don’t agree on everything.

“One of the advantages of our research team is that we do have a lot of diversity of views, and that ends up making our papers better,” she says. “We didn’t choose to work together.”

Stress in Toddlers

While the closely watched NICHD study has captured considerable media attention since it began more than 10 years ago, other new research on the effects of child care is being conducted.

Megan R. Gunnar, a professor of child development at the University of Minnesota-Twin Cities—whose work also appears in the same summer issue of Child Development—found that adjusting to the social dynamics of a toddler classroom can be a stressful experience for a young child.

Gunnar and her colleagues collected saliva samples to measure levels of the stress hormone cortisol in small groups of infants and toddlers while they were in child-care centers for a full day. The levels were tested again in the afternoon, once they were home.

Cortisol levels increased in 35 percent of the infants while they were in care, and decreased in 71 percent of them after they were home. Among the toddlers, who averaged about 21/2 years old, there were increases in 71 percent of them in the morning, and decreases in 64 percent of them after they went home.

The cortisol levels were lower in toddlers who played more with their peers, suggesting that those children had developed some “social competence,” the researchers write. The levels were higher, however, in toddlers who tended to keep to themselves during the day.

The authors note that it is not fully understood whether minor increases in cortisol levels pose any risk to young children. But they add that “in the absence of knowing whether these rising cortisol levels over the child-care day do affect developing neural systems, it is probably prudent to understand the factors that contribute to them and consider whether and how they can be reduced.”

Although similar studies have been conducted involving older children, the researchers explain in the paper that they wanted to study toddlers “in classrooms where peer play is beginning to be an important activity.” And they accurately predicted that the stress levels would be lower for infants, who do not yet play with other children.

“Toddlers, unlike infants, focus considerable attention on other children, attempt to play, but have only rudimentary play skills, particularly in the early toddler period,” the study says.

Cortisol levels were also higher in both infants and toddlers who were considered by their child-care teachers to have more fearful temperaments.

“This finding suggests that infants and toddlers who are more socially fearful ... may find the social context of child care particularly challenging,” the authors write, adding that baseline cortisol levels may be higher in shy, inhibited children.

The researchers acknowledge that there are limits to the findings. For example, the authors did not examine whether cortisol levels also increase for young children who are in other out-of-home settings, such as family child-care homes. The role that the quality of the child-care setting plays is also not fully understood, they write.

In one of a series of commentaries that appear in the same issue of the journal, Douglas A. Granger, an associate professor of biobehavioral health at Pennsylvania State University, in University Park, argues that the interpretation of studies involving testing a child’s saliva is “rarely straightforward,” and that behavioral scientists need to use multiple research methods.

He suggests that it is important for researchers to measure levels of other hormones as well. And he adds that more needs to be learned about hormone- behavior relationships “within the context of the family.”

‘Complex Interplay’

But what’s significant about Gunnar’s research is that it may help both parents and policymakers better understand the NICHD findings on aggression.

Susan C. Crockenberg, a psychology professor at the University of Vermont, in Burlington, wrote in another commentary in the same journal that children’s individual characteristics should be considered when child- care settings are studied. Those differences can explain why the experience is stressful for some children, but not for all of them, and why some develop more aggressive traits and others do not.

Both the NICHD and the cortisol studies, Crockenberg writes, “demonstrate the complex interplay of the amount, type, and quality of child care that in conjunction with children’s temperamental characteristics predict differences in physiological stress and behavior problems among young children who experience child care before age 5.”

The link between child care and aggression is not unique to children in the United States. In the first longitudinal study of preschoolers in the United Kingdom, researchers at three universities released data earlier this year showing an association between “high levels of group care before the age of 3" and higher levels of antisocial behavior at age 3. This connection was even stronger when children spent large amounts of time in child care before age 2 and when children attended local government-financed or private “day nurseries,” which care for children from infancy through preschool age.

Called the “Effective Provision of Preschool Education,” the study also found another familiar conclusion: Children who spent more time in group care showed higher cognitive skills than those in other arrangements. The researchers also found that attending a high-quality child-care or preschool program after age 3 mitigated the negative behavior.

Unlike the NICHD study, the U.K. study did not enroll children at birth, but parents were interviewed about children’s experiences before age 3.

Researchers both here and abroad say, however, that while using child care is often necessary, parenting still has the strongest influence on a child’s development.

In fact, in a summary on the findings of the U.K. study, the researchers write that the “home learning environment can be viewed as a ‘protective’ factor in reducing” later school problems. And they found only a small connection between what parents do to create positive family experiences and the mother’s educational level.

“In other words, what parents do with their children is more important than who the parents are,” the authors write.

The extent to which children are negatively affected by their time in child care might also have a lot to do with the quality of their time at home, suggest Lieselotte Ahnert, a professor of education and developmental psychology at the Free University Berlin, and Michael E. Lamb, the chief of the NICHD’s section on social and emotional development.

“Maladaptive behavior on the part of children who spend many hours in child care may reflect not the direct effects of nonparental care, but the inability of parents to buffer the enhanced levels of stress experienced in child care,” they write in a paper that also appeared in Child Development.

Longitudinal Sample

With its National Early- Childhood Longitudinal Study, which includes a sample of more than 10,000 children born in 2001, the U.S. Department of Education will also be able to provide the public with more information on the types of child care young children are experiencing and how it affects them.

Researchers at the department’s National Center for Education Statistics are currently analyzing data collected on the children when they were 9 months old and plan to begin publishing findings next spring.

According to Jerry West, the program director for early-childhood and household studies at the NCES, a sizable number of the children had already been in some form of child care during their first year.

While the researchers are collecting similar kinds of information on the children and their families as the NICHD team did on its sample, findings from the NCES study are likely to be more robust simply because the sample is 10 times as large and is nationally representative.

West adds that the NCES study will also provide a closer look at groups within the sample. For example, a larger-than-typical number of American Indian children were enrolled in the study to capture a better picture of their early experiences.

Even with all the data that the NICHD investigators and other researchers are gathering and analyzing on children, they probably won’t be able to find out everything parents and policymakers want to know about the risks and benefits of organized child care, Pianta of the University of Virginia says.

But he adds: “We’re certainly going to learn how complicated it all is.”

The Research section is underwritten by a grant from the Spencer Foundation.