When Should Kids Start Kindergarten?

Soon-to-be 5-year-old Michael Kepner is bright boy who loves playing with his building blocks.

But there's one small difference between him and most of his classmates: his height.

Michael is in about the 10th percentile, which means about 90 percent of kids his age are bigger than him. Michael's height is the big reason the Kepner has chosen to keep him back. He won't go to kindergarten this year like 3 1/2 million other American children his age. Instead, he will spend one extra year in pre-school.

"It's not because I want him to go Harvard or I want him to start on the varsity basketball team, it's just because kids are under so much pressure and I just want him to have every advantage I can give him," she told The Early Show national correspondent Jeff Glor.

On the flip side, 5-year-old Fiona's mother, Patti McCormick, chose a different route.

"We recently met with the teacher and she said she's doing great, there's absolutely no reason to hold her back. She's reading. She's on par with everyone else. She's doing a great job," she said.

Clinical director of the Institute for Learning and Academic Achievement Susan Schwartz says parents don't need to get as worked up about this decision as many do. She said research has found that children's development seems to even out by the third grade.

"There isn't a big difference between those children who have been held back and those children who have moved on — who have gone to kindergarten at age 5," she said.

Schwartz, who is also an assistant professor at the NYU School of Medicine, says parents might feel pressure about kindergarten not only because of the competitive nature of our society, but also because school districts are trying to make their curriculum more challenging. In many cases, she said, kindergarten now seems like first grade. This is exacerbated by the emphasis on testing in No Child Left Behind.

"I think specialists are forgetting, teachers are forgetting, that work — play is child's work," she said. "And that they need to develop by doing and being actively involved in various activities."

Even still, it's hard for parents not to worry. One child is moving on and one is staying back, which begs the question: what's best for your child?

Dana Gorman, a pre-school director and teacher in Connecticut, says parents across the country grapple with this decision every year.

"They worry about what to do. They don't want their children to have to repeat or to hold back. They want their children to stay with their friends and go to school with their friends that they've made in preschool, so they really worry about it. It's an important decision and they want to do right by their children," she said.

Gorman says parents should consider things like the child's age, maturity, reading ability, and social skills.

The National Center for Education Statistics found that close to 10 percent of 5-year-olds are academically redshirted — the term coined to describe this growing trend of holding kids back a year. Boys are twice as likely to be redshirted as girls.

Kids in more affluent areas are more likely to delay than in poorer areas because their parents think it will give them an edge.

"It's tough you don't know what the right thing is to do because the guidelines that are in place, you could send a child early or you could send a child later," Gorman said.

Even moms like Kempner, who can afford to keep her child back, admit that only one thing can solve this dilemma.

"I think there should be a national standard. I think they should say by the time kindergarten starts you should be 5, whenever kindergarten starts, and everybody should have to stick to that," she said.

Schwartz said there are some important things to consider when making this decision: