What to wear? Schools increasingly making that decision

• Nearly one in five public schools mandated uniforms in 2010%2C up from one in eight a decade earlier
• More than half of public schools now enforce dress codes
• No strong evidence that uniforms improve kids%27 behavior or academic standing

As students head back to school in the next few weeks, they're more likely than ever to arrive dressed in a school-sanctioned uniform, an increasingly popular policy that may not improve schools as advertised.

Nearly one in five public schools required uniforms in 2010, up from just one in eight a decade earlier, according to the most recent findings from the U.S. Department of Education. The 60% growth in uniform requirements at school comes despite the fact that research on their effectiveness for safety and school climate is inconclusive.

Overall, more than half of public schools enforce some sort of dress code, according to the National Center for Education Statistics. About 57% of schools now have a "strict dress code," researchers found, up from just more than 47% a decade earlier.

The idea of requiring public school students to wear uniforms was first envisioned in the 1980s by then-Washington, D.C., mayor Marion Barry, who believed standardized dress might help public school students succeed as well as those in the city's Catholic schools. The idea flopped, but in 1987, Cherry Hill Elementary School in Baltimore implemented the first known schoolwide uniform policy "as a means of reducing clothing costs and social pressures on children," writes David Brunsma, a Virginia Tech sociologist and author of the 2004 book The School Uniform Movement and What It Tells Us About American Education. School officials hoped uniforms would lead to "better grades, better behavior, increased self-esteem and school pride," he says.

But Brunsma's review of nearly a decade's worth of research found that uniforms' effects were either unknown, statistically insignificant or, in the case of a few studies, negative. In one study, uniforms correlated with more negative perceptions of school safety and climate by middle-school principals. In another, they were associated with worse academic results in 10th grade.

Brunsma calls school uniforms "a policy that is simplistic, readily understandable, cost-free (to taxpayers) and appealing to common sense," but which made it impossible to implement more costly solutions that "demand energy and a willingness to change on the part of school faculty and parents."

Longtime school safety consultant Ken Trump said educators like uniforms because they simplify their jobs, saving them from having to punish kids for too-short skirts or shorts, for instance.

"Kids are trying so hard to one-up each other on everything from hair styles to shoes," he says. "It takes away the daily fashion show and helps level the playing field a little bit with the haves and have-nots."

Trump's children attend a Cleveland-area Catholic school and are allowed to show up out of uniform as an occasional reward for good behavior. He says administrators there tell him the school climate deteriorates when too many kids are out of uniform.

Trump, who has been consulting with schools in Ohio and elsewhere for nearly 30 years, said uniform policies are often unpopular with parents at first but that parents come to appreciate them.

"A couple of months down the road, the parents absolutely love it because they spend a whole lot less time fighting with their children over what they're going to wear," he says.

Despite what the research might suggest, uniforms remain popular with educators, he says. "I've never heard a school administrator whose school went in the direction of uniforms say, 'This has created more problems for us.' On the contrary, it's been a blessing."