WEDNESDAY, July 17, 2002 (HealthDayNews) -- Babies under the age of nine months whose mothers go back to full-time work may suffer later when it's time to go to school.
These children scored several points lower on a school readiness test at age 3 than those whose mothers had stayed home during their first year.
An early childhood test, developed by psychologist Bruce A. Bracken, assesses skills like color and shape recognition and familiarity with letters and numbers, but it doesn't measure learning ability. Indeed, children whose mothers worked more and sooner didn't seem to lag in emotional or intellectual development, the researchers said.
However, worse scores on the school readiness test may translate into poorer scores on standardized tests at ages 5 through 8, the researchers explained.
"We are finding this effect in multiple studies, which leads me to believe there really is something there," said Jeanne Brooks-Gunn, a researcher at Columbia University Teachers College and lead author of the study.
The study appears in the latest issue of Child Development, a publication of the Society for Research in Child Development. It's part of a government-sponsored study looking at the effects of child care, maternal sensitivity and other variables on early childhood development.
Working part time -- defined as fewer than 30 hours a week -- was not associated with worse scores on the school readiness test. Having top quality day care and being "sensitive" to one's children went a long way towards narrowing the gap, the researchers said. But it couldn't erase the effect completely.
"Our message is, working full time in the first nine months may have some risks, and if you are working full time, think about being as responsive [to your child] as you can and try to purchase the highest quality day care you can," Brooks-Gunn said.
The new findings both parallel and diverge from earlier reports. And they'll doubtless be as welcome to many women as a temper tantrum.
But the research does suggest that policies to hurry new mothers back into the workforce may have adverse consequences for their children. By 1998, nearly 6-in-10 American mothers were back at work by their child's first birthday, almost twice as many as in 1976.
Brooks-Gunn's group compared mothers' working habits with a variety of developmental measures in 900 white boys and girls. Maternal education, family income and number of siblings all affect a child's development, as do many other factors. So, the researchers tried to take these factors into account.
To make their results easier to present, they performed a simulation to project the effects on school readiness tests of several variables, from the quality of child care to the strength of the bond between a mother and her infant.
Using this model, the kids who had the most trouble on the school readiness test, scoring in the 36th percentile, were those whose mothers went back to work more than 30 hours a week within nine months of giving birth, whose day care was below-average quality and whose home environment and maternal sensitivity were in the lowest quarter.
Those whose mothers delayed working and who had average home environment and maternal sensitivity scored in the 49th percentile. That was roughly six percentage points higher than infants in similar situations whose mothers worked more than 30 hours a week. [The highest scoring children, in the 56th percentile, had mothers who delayed working, had above-average day care and were in the top quarter of maternal sensitivity and home environment.]
Jane Waldfogel, a Columbia social worker and a study co-author, said the real-life effect of a six-point difference is difficult to assess.
"But if we could come up with an intervention that would raise it six points, we would be very happy," she added.
The researchers said no particular skills appeared to suffer more than others.
John Hagen, a University of Michigan psychologist and executive officer of the Society for Research in Child Development, called the difference "significant but not dramatic" and said that "for the majority of kids, it's not going to make that much difference."
Hagen added that the findings aren't surprising, but they do deserve attention. "It might be better [for some children] if mothers didn't have to go back to work full time" so quickly, he said.
Having a father at home more might help reduce the effect of mom's absence, Hagen said. The researchers said too little is currently known about the benefits of stay-at-home dads.
Martha Cox, director of the Center for Developmental Science at the University of North Carolina, said the new study won't be a 'gee whiz' for most families.
"Working during the first year of [a baby's] life is very challenging for a family," said Cox, who has analyzed the same data as the Columbia researchers.
She noted that, at first glance, children whose mothers go back to work early appear to do better than those whose mothers stay at home. That's because women who don't work tend to have lower family incomes and more bouts of depression, both strikes against their babies.
Only after accounting for factors like a mother's education level, income and how often she's depressed do the kind of differences' Brooks-Gunn's group found surface. In other words, social scientists must iron wrinkles into averages to draw out the effect.
However, Cox added, "I don't think this negates our paying attention to these findings at all. This analysis points out that these early months of a child's life are probably particularly difficult for a family to negotiate, and we may need to be giving families more of a break."
Indeed, Waldfogel noted that the study has implications for family leave laws, welfare policy and the push to require women receiving public aid to work more.
States now have the option of requiring women on welfare to go to work once their babies are at least three months old, but even then they can only demand a 20-hour week, she said. That ceiling would rise to 40 hours a week under a proposal now being considered.
"That's a lot of hours given these findings," Waldfogel said.
What To Do
For more on child development, visit the Society for Research in Child Development. For more on family leave law, try the U.S. Department of Labor.
