Link Found Between Behavioral Problems and Time in Child Care
By SHERYL GAY STOLBERG
WASHINGTON, April 18 —
Researchers conducting the
largest long-term study of child
care in the United States said
today that they had found that
children who spend most of their time in child care are three
times as likely to exhibit behavioral problems in kindergarten
as those who are cared for primarily by their mothers.
The study followed more than 1,100 children in 10 cities in a
variety of settings, from care with relatives and nannies to
preschool and large day care centers. Its conclusions are based
on ratings of the children by their mothers, those caring for them
and kindergarten teachers.
The study, whose detailed results have not been published,
found a direct correlation between time spent in child care and
traits like aggression, defiance and disobedience. In interviews
today, two of its lead researchers said the findings held true
regardless of the type or quality of care, the sex of the child, the
family's socioeconomic status or whether mothers themselves
provided sensitive care.
"As time goes up, so do behavior problems,"said Dr. Jay
Belsky, one of the study's principal investigators.
Dr. Belsky said children who spent more than 30 hours a week
in child care "are more demanding, more noncompliant, and
they are more aggressive." He added, "They scored higher on
things like gets in lots of fights, cruelty, bullying, meanness, as
well as talking too much, demands must be met immediately."
The research, financed by the National Institute on Child Health
and Human Development, a branch of the National Institutes of
Health, has not undergone the rigorous scientific evaluation
known as peer review. But the long-running study is widely
regarded as the most comprehensive examination of child care
to date. In 1996, the same group of researchers concluded that
using day care centers or baby sitters did not affect infants' trust
in their mothers.
Dr. Belsky said he would present the findings on Thursday in
Minneapolis at a meeting of the Society for Research in Child
Development. His announcement will undoubtedly inflame a
debate that has continued for years over whether it is better for
mothers to work or stay home. Dr. Belsky helped set off that
debate in 1986 when he published an article suggesting that
child care posed a risk of developmental problems.
Some experts on work and family life are already questioning
the study's results. Perhaps, said Ellen Galinsky, president of
the Families and Work Institute, a nonprofit research
organization in New York, "it's not being in child care that is
the problem, it's that employed parents are tired and stressed."
And Claudia Wayne, former director of the Center for the Child
Care Workforce, a group that advocates improving the quality
of child care, suggested that quality might indeed be an issue
because most child care was mediocre.
Thirteen million preschoolers, including six million infants and
toddlers, are in child care in this country, according to the
Children's Defense Fund in Washington. Nearly 30 percent of
American children are in child care centers, while 15 percent
are with family child care providers and 5 percent are with
in-home caregivers, the organization says. Another 25 percent
are cared for by relatives, which was defined as child care in
the N.I.H. study. Roughly one- fourth are cared for by their
The researchers conducting the study did not have an
explanation for why some children in child care might become
more aggressive or disobedient. "That is the most pregnant
research agenda," said Dr. Belsky, a developmental
psychologist who two years ago left Penn State University, one
of the study sites, for the University of London.
But they do have some theories, said Dr. Sarah Friedman, who
is coordinating the project for the child health institute. It is
possible, she said, that child care providers are not trained to
give emotional support. And Ms. Galinsky's explanation, that
parents are overworked, is a plausible one, Dr. Friedman said.
The researchers are tracking the children to see if the problems
persist, and they cautioned against drawing conclusions that
children in day care would turn out to be violent.
Dr. Friedman said the children's behavior, while demanding
and aggressive, was "in the normal range," not so severe it
required medical attention.
"We cannot and should not hide the findings," she said, "but I
don't want to create a mass hysteria when I don't know what
explains these results."
The study, called the N.I.C.H.D. Study of Early Child Care,
began in 1990 in 10 cities, including Little Rock, Ark., Irvine,
Calif., and Charlottesville, Va. It defined child care as care by
anyone other than the child's mother that was routinely
scheduled for at least 10 hours per week.
When the researchers examined behavioral ratings for children
who were in care for more than 30 hours per week, they found
that 17 percent of them were regarded by teachers, mothers and
caregivers as being aggressive toward other children. That is
compared with 6 percent for the group of children in child care
for less than 10 hours a week.
There were some surprising findings. Children who spent more
time in child care were initially rated as being more fearful and
sad than other children, but the differences disappeared by
And there was one positive note: children who spent more time
in child care centers, as opposed to other types of child care, in
the first four and a half years of life were more likely to display
better language skills and have better short- term memory. The
researchers said they had not teased out whether these children
were the same ones who were at increased risk of behavioral
April 21, 2001
Public Lives: Another Academic Salvo in the Nation's 'Mommy Wars'
By SHERYL GAY STOLBERG
WASHINGTON - Jay Belsky
was 33 years old, a rising
young star in the discipline of
human development, when he
received what he now calls "my
lesson in the science of political
correctness and the Mommy
The year was 1986; Dr. Belsky
was an associate professor at
Pennsylvania State University.
Eight years earlier, he had won
accolades for research showing
that, despite the anxiety over child
care, the children were not
suffering. Working mothers everywhere had breathed a sigh of
And then their savior changed his mind.
"A slow, steady trickle of evidence," Dr. Belsky recalls, had
built up to persuade him that infants who spent long hours in
child care were at risk of behavioral problems later on. He
published his views in a little-known newsletter, under the
headline "Infant Day Care: A Cause for Concern?" And he
opened with a personal disclaimer: his two young sons were
cared for by their stay-at-home mother.
It was as if he had advocated infanticide.
"I was a pariah," Dr. Belsky says, "a phantom."
Colleagues shunned him at scientific meetings. A textbook he
co-wrote wouldn't sell; the publisher removed his name from
the second edition. Critics called him a misogynist, and worse.
At the height of the frenzy, Dr. Belsky remembers, he gave a talk
in New York. Scanning the crowd, he felt a flash of paranoia: "I
thought, somebody is going to walk down this aisle and shoot
This week, Dr. Belsky, now 48 and a professor at the
University of London, felt those old twinges once again. This
time, the city was Minneapolis. There he presented results from
a comprehensive study of child care, led by more than a dozen
researchers and paid for by the National Institutes of Health,
that was initiated a decade ago, largely to address criticisms of
his earlier work.
Once again, the news was not upbeat: the more time young
children spent being cared for by someone other than their
mothers, the more likely they were to be aggressive, demanding
and disobedient as kindergartners. (In the group studied —
1,100 children in 10 cities — only a small amount of care was
provided by fathers, Dr. Belsky said.)
And once again, Dr. Belsky, now feeling ever so slightly
vindicated, is ruffling feathers. In an interview, he seemed as
though he rather enjoys it. Or at least, he has gotten used to it.
"I'm not a person who is the least bit hesitant to say the
politically incorrect thing, to challenge the status quo," he said
early Friday morning, having spent the previous day making the
rounds on television. "I have a reputation of being a difficult
person. But one of the reasons I'm a difficult person is because I
won't lie down and play dead."
That difficult streak did not begin in childhood, Dr. Belsky
believes; he describes himself as quite straight-laced and
dutiful as a boy. He grew up on Long Island, in Valley Stream.
His parents owned a luncheonette on 39th Street in Manhattan,
and he fondly recalls working summers there.
"I can say, in complete objectivity, that my father's corned beef
and pastrami sandwiches rivaled those of all the famous delis."
As a child, he dreamed of attending West Point — not to
become a soldier, but "to serve my country." He applied and
was accepted, only to decline because he had concluded that the
Vietnam War was misguided. He wound up instead at
Georgetown University, where, he says, he was struck by "a
classic identity crisis" that was resolved when he spotted a
classmate with a bunch of preschoolers in tow.
"Where did you get those?" Dr. Belsky remembers asking,
somewhat flippantly. His friend, it turned out, volunteered at a
campus day care center.
In short order, Dr. Belsky signed up. He had found his calling.
He transferred to Vassar College, because it had a nursery
school, graduated in 1974 and went on to obtain a doctorate in
human development at Cornell, where he wrote the child care
paper that brought him his initial acclaim.
When he joined the faculty of Penn State, he and his wife, Ann,
from whom he is now divorced, helped create an infant
day-care program. But around the same time, Dr. Belsky said,
his review of the literature on child care began to nag at him.
One study, he said, linked child care to tantrums, a finding he
and others had dismissed because it was based on mothers'
reports. Another connected child care to problems with the
infant-mother bond, but was discounted because it involved
only the poor.
"It got to the point," Dr. Belsky said, "where I felt like a pretzel,
twisting and turning, trying to explain these things away. By
1986, I said, `I can't do this anymore.' "
TODAY, some of the same scientists who attacked Dr. Belsky's
1986 warning as ill-considered and flawed are his co- authors
on the N.I.H. research. Most of them are women, and Dr. Belsky
is not shy about saying he thinks he breeds extra resentment
because he is a man.
He notes, quite pointedly, that while he was criticized for
keeping his children out of day care, his colleagues were never
criticized for putting theirs in.
As for the study's findings, researchers have still not answered
the biggest question: what might cause a link between day care
and aggression? The study ruled out socioeconomic status and
quality of care, although some of Dr. Belsky's co-authors still
think quality is a factor. He bristles at the suggestion, yet says at
the same time that the days of his "knockdown, drag-out battles"
appear to be over.
"At least," he said, `'I don't feel like I'm being hung in effigy
April 22, 2001 - NYT
Science, Studies and Motherhood
By SHERYL GAY STOLBERG
BEFORE working mothers
drown themselves in guilt
over the release last week of a
study that said children who spend
long hours in child care are more
likely to have behavioral problems
in kindergarten, they should stop
and consider not only what science
can reveal, but what it cannot.
Studies of human behavior make
good headlines, but they can be
fraught with complications. Earlier
this year, for example, a team at
Stanford University published a
study showing that children who
cut back on television and video
games were less likely to tease or
bully their peers during recess.
But a lot of things influence the way children behave at recess
— whether they ate enough for lunch, or who they sat with. So it
is difficult, experts said, to measure the influence of video
Divorce is another case in point. In recent years, researchers
have compared children of divorced couples to those whose
parents stuck together despite marital strain and concluded that
those in intact families fare better. But James Robins, a
professor of epidemiology and biostatistics at the Harvard
School of Public Health, says such studies are inevitably
"It's not a fair comparison," Dr. Robins says. "You are almost
certainly going to find that children of divorce do worse
because the people who get divorced are probably the people
whose fighting is worse. So even if the truth was that it is better
for parents to divorce, you would get the wrong answer."
Most experts agree the new child care study, the largest of its
kind ever conducted, is extremely rigorous. But even the
researchers who conducted it say it raises as many questions as
it answers. For instance, the study looked only at time spent
away from mothers, not fathers. And though it found 17 percent
of children in long-term child care experienced behavioral
problems later on, 83 percent of them did just fine.
The study was what epidemiologists call observational
research, as opposed to a controlled experiment. In a controlled
experiment, children would have been compared after being
assigned, or "randomized," to child care or home with their
mothers. That would be unethical, so researchers drew
conclusions based on their own observations and those of
mothers, caregivers and kindergarten teachers.
But there is "a potentially fatal flaw" with observational
studies, says Donald Berry, chairman of the department of bio-
statistics at the University of Texas. "Inferring cause and effect
is not possible."
So even though the study was paid for by the National Institutes
of Health, the nation's premier scientific institution, and
conducted by some of country's most respected child
development experts, there are holes in it. It shows only a link
between time spent in child care and aggressive behavior. It
does not explain why a youngster in child care might be more
likely to be aggressive or disobedient. And it certainly does not
prove that child care itself is the cause.
"Maybe the kind of mothers who put their children in day care
are more stressed out, and the child feels some of the stress,"
said Dr. Robins, the Harvard epidemiologist. "Maybe women
are more likely to put rambunctious kids into day care, and so it
is the selection of kids who have problems being put into day
care, rather than day care causing problems. That's what you
can't tell from observational studies."
And controlled experiments often prove observational studies
wrong. For example, Dr. Berry notes that, based on
observational studies, thousands of women were given bone
marrow transplants for breast cancer. Insurance companies paid
for the costly and drastic procedure. But two years ago, a series
of randomized experiments showed the transplants were no
better than conventional therapy.
Science is like a puzzle, says Dr. Christopher Forrest, associate
professor of pediatrics and health policy at Johns Hopkins
University. "Until you fill all the pieces in, you can't say a
relationship has been proven."
And how do you fill the pieces in? The finding has to be
reproduced, and the researchers need to discover a mechanism,
a plausible explanation for their results. Dr. Forrest points to
the case of lung cancer and cigarettes.
The initial evidence, he said, was observational. Scientists
found a "dose-response relationship" between smoking and
disease: the more a person smoked, the greater the likelihood of
sickness. They found a temporal relationship: smoking preceded
cancer. But still, the tobacco industry could claim that there was
no proof. That did not change, Dr. Forrest said, until molecular
biologists showed smoking caused genetic changes in the lung.
Now, he said, the industry "can no longer say there is no
connection, it's not proven."
"They had that last piece of the puzzle," he said.
THE child care researchers do have some pieces of the puzzle
in place. Their study, like the early lung cancer research, found
a dose-response relationship: the more time a child spent in
child care, the greater the likelihood there would be behavioral
problems in kindergarten. But determining what causes a
behavior can be even more complicated than determining the
cause of a disease. And the researchers themselves have very
different ideas about where to look.
Dr. Jay Belsky, of the University of London, who presented the
results last week in Minneapolis at a meeting of the Society for
Research on Child Development, speculates that the
psychological stress children experience at the end of the day,
when they are reunited with their parents, might breed
aggression and disobedience. But another principal
investigator, Dr. Deborah Phillips, of Georgetown University,
has an entirely different theory: although the study found quality
of child care made no difference, she thinks a closer look will
show that mediocre care is to blame.
These nuances, of course, are lost in the sound-bite debate the
findings have generated. We live in a whipsaw world, where
scientists produce a dizzying stream of research, and each new
study seems to contradict the previous one. Is estrogen good for
heart disease, or isn't it? Do cell phones cause brain cancer, or
don't they? Scientists trust that the answers to such questions
will emerge over time, through the accumulation of a body of
evidence. But the public wants answers now.
"The public reads the bottom line," Dr. Forrest says. "They act
on that without putting the study into context. In politics, there is
always a context. The same is true for science, but it doesn't get
reported that way."
|A day care center, the sort of place in which bullies are bred, according
to a new study.
Angel Franco/The New York Times