Robby Hoch is energetic, curious and outgoing, much like the other kindergartners at Creek Valley Elementary in Edina. Except for one thing: He's a year older than most of his classmates. In his mom's eyes, that's a good thing.

"We wanted to give him that extra year to mature socially, and to set him up to succeed later in life," Katy Hoch said of her choice to start her son in school at age 6 instead of 5, because of his late August birthday. "He probably could've handled starting at age 5, but when he turns 12, 14, 18 -- and even in college -- it's going to be an advantage for him to be a year more mature."

The practice, sometimes called "academic redshirting," is a term borrowed from college sports where athletes are benched for a year to give them time to develop their skills. In the early 1990s, about 9 percent of U.S. kindergartners were purposefully held back each year, according to the National Center for Education Statistics. Today, the percentage is nearly twice that.

At Grey Cloud Elementary School in Cottage Grove, about 5 percent of the students who are 5 by Sept. 1 choose not to attend. Statewide, the number is closer to 12 percent, putting Minnesota just under the national average.

With schools' increasing emphasis on academic achievement and society's growing concern for kids' emotional needs, more parents like Hoch are considering holding their children back a year until they're more physically, academically and emotionally ready. But early educators fear too many are adopting that philosophy and for the wrong reasons.

"Parents carry a lot of anxiety about this decision, especially if their child is born in June, July or August," said Laura Loshek, a former kindergarten teacher and now principal at Grey Cloud Elementary. "If the child ends up struggling, parents feel guilty about sending them. They always wonder if they did the right thing."

Conflicting research

At Breck, a private school in Golden Valley, roughly 23 percent of kindergartners will turn 6 by the end of October.

"There's a general momentum in society that kids need to have a leg up," said Peg Bailey, Breck's lower school director. "Parents are in a state of confusion about what to do because there's no real supporting research that says this is a good idea."

Parents are anxious for good reason. The research shows both benefits and drawbacks. Some studies say that students who start a year later have a slight academic edge and better test scores than their younger classmates, and are more likely to be classroom leaders.

Other research has found that children who were redshirted were less motivated and more likely to have behavioral problems later.

Some of the latest research, published in the Society for Research in Child Development, indicates that parents might be agonizing for nothing. While students who enter school later might initially produce better test scores, the advantages fade by the end of elementary school, indicating that the age at which a child starts kindergarten makes little difference in the long run.

Still, the subject continues to be hotly debated in preschool groups, mommy play dates and education blogs.

Malcolm Gladwell's 2008 book "The Outliers" launched redshirting into the spotlight by looking into what makes people successful. Some of his research found that the majority of Canadian junior hockey all-stars had one thing in common: Most of them were born in the first half of the year.

Gladwell compares his findings to a 2006 study by economists Elizabeth Dhuey and Kelly Bedard that discovered a relationship between the age of entering school and academic performance. The oldest students attained percentile rankings four to 12 points higher than the youngest students at the fourth-grade level and two to nine points higher at the eighth-grade level across a range of countries.

The book resonated with Karin Gessner of Eden Prairie. Her 2-year-old son has an August birthday and already Gessner knows she will be keeping him at home until he turns 6.

"I'd hate for him to be on the lower end of the scale just by virtue of his age,'' she said. For me, it has nothing to do with sports, though I have heard many moms talk about that."

More a whisper than a shout, athletics and academics are increasingly the motivation to redshirt, especially among boys in higher performing suburban schools. During her research of early literary performance at the University of Minnesota, Alisha Wackerle-Hollman met many parents who kept their children out of school until age 6, because they wanted them to have a competitive edge over their younger peers, especially if they were hockey parent hopefuls.

An educational psychologist, Wackerle-Hollman advocates for children being in the classroom earlier rather than later -- but for the right reasons.

"Instead of considering the challenges a child faces from being the youngest in class, consider the benefits of having them in an academically fulfilling environment for a whole year that they might not get at home," she said.

To redshirt or not?

Redshirting could be exactly the right thing for a kid, but some educators say the practice is getting out of hand. Megan Durkin has been a preschool teacher for more than 25 years and said it's this newest generation of parents who are rushing to redshirt. Now the owner of Montessori Children's House in Northfield, Durkin often advises parents she describes as "overanxious" about sending their children to school.

"It's an abnormality in the education system to have a whole year's age difference in each grade," Durkin said. "It's not as strange at an elementary age, but as the redshirted students get older, they do stick out. They look like a red shirt in the middle of a sea of other colors."

Catherine Scharlau, a psychologist with Aspen Medical Group, regularly sees parents who are in a quandary about when to start their children in kindergarten.

Her advice? Don't base the decision on one factor alone; consider every aspect of a child's development.

"Academic readiness at age 5 isn't a very clear indicator because so many academic differences wash out by third grade. Looking at all aspects of their development is truly important," Scharlau said. "It's a complicated question and needs to be handled on a very individualized basis."

Kim Kotzen Wear did just that and kept her son, Gabriel, out of school until he was 6 and has never looked back. Wear said her son, who is shy and has a July birthday, would have been at a disadvantage.

She believes the extra year of preschool better prepared Gabriel, who's 7 and now in first grade, to be a leader in his class and handle the long day.

"Everyone told me it would be the best decision I'd make and I wouldn't regret it," Wear said. "It's a gift you can give your kids -- the gift of time."

Aimée Blanchette • 612-673-1715