That was despite some small improvements in parenting behavior that researchers saw during the original study of their older siblings.

"It was thought, well, you've provided the parents with some very specific guidance about how to look at developmental accomplishments and how to foster them... and so maybe there would be some benefits for the younger sibling," said Dr. Marie McCormick, the study's lead author from the Harvard School of Public Health in Boston.

The initial study, conducted at eight sites including New York, Miami and Dallas, involved weekly or biweekly home visits focused on child development and education in day care centers for toddlers age one to three. All of the kids had been born at a low birth weight and so were at risk for developmental problems later on.

From that early education program, researchers noticed improvements in parents' disciplinary strategies and at least short-term effects on IQ and behavioral problems for the kids involved. And they had hoped those findings might mean the younger siblings of preschoolers that went through the program would end up better off, as well.

Out of 878 kids in the first round of the study, 229 had siblings born within five years of them who agreed to participate in the new research and took questionnaires and intelligence tests at age 13 or 14.

Scores from another 237 teens whose older siblings hadn't gone through the day care and home-visiting program were used for comparison.

There was no difference in the IQ scores of those kids: younger siblings of the early education group averaged 89.7 on the test, compared to 92.7 in the comparison group (100 is the average score). The two were also similar on measures of their behavioral problems and expectations about their own future success, McCormick and her colleagues reported Monday in the Archives of Pediatrics & Adolescent Medicine.

DIFFICULT TO CHANGE PARENTING

The researchers note that they didn't have information on early health or education for younger siblings that completed the questionnaires, which could have affected the findings.

Still, improving the outlook for younger siblings by changing parenting is "something that is very difficult to do," said W. Steven Barnett, head of the National Institute for Early Education Research at Rutgers University in New Brunswick, New Jersey.

"We know that parents are very powerful. We also know that we have a very difficult time changing parental behavior," Barnett, who wasn't involved in the new study, told Reuters Health.

"I think what this suggests is the biggest impact of the program is through the (day care) part, and if the sibling does not go to the center, the sibling does not get a lot of impact."

He said that's consistent with earlier studies that found extra help for one kid typically doesn't benefit others in the family.

McCormick said the program may have focused too much on children, and not their parents, to expect to see long-term improvements in parenting practices. Other than how moms disciplined their kids, the researchers didn't see any significant changes in parents' education or expectations, she told Reuters Health.

"This just suggests that one of the benefits (of early education programs) is not going to be the spillover effects on siblings," McCormick said.

"Particularly for families that are stressed… it may be very difficult without the help of a home visitor to go through this step-wise process every week that they learned," she added.

That may mean that younger siblings will have to be targeted with their own home visiting or day care programs to see improvements in their long-term outlook, according to McCormick.

SOURCE: bit.ly/KEGTVv Archives of Pediatrics & Adolescent Medicine, online June 4, 2012.

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