BOISE, Idaho — This fall, uniforms are coming to a public school here in our town for the first time ever, and have created a stir. My family, however, has been through this before.

While spending a year in the coastal Mexican city of Zihuatanejo last year, our kids, now 6 and 7, wore uniforms at their private school. And to us — as to many Boise residents now — the idea took a little getting used to.

The uniforms in Mexico were red plaid, with puffy white blouses trimmed with more plaid, and reminded me of old pictures of British boarding schools. There was even a red, blue and gold bathing suit, with matching cap, bearing the school crest.

The many other small public and private schools around town required similar outfits, only in different colors. In Mexico, it sometimes seems as if everyone wears a uniform — even the workers at the smallest taco stand often have a company logo on their T-shirt.

But for us, as Americans, it was a bit of a jolt. In the United States, school uniforms seem to be one of those education trends that come and go. Catholic schools often have them. Many private schools do too.

As it turns out, however, more and more U.S. public schools have been adopting them in the last decade or so.

At Boise's South Junior High School, as in many places, the decision to introduce uniforms was made in an effort to tone down social divisions and steer adolescents away from belly-baring shirts and microscopic minis. Principal Kathleen McCurdy settled on maroon polo shirts and khaki or black skorts, skirts or pants for the school's 750 students.

Compared to Mexico, it's a pretty laid-back dress code.

"We already kind of like dress that way," said Cody Bird, 14, who starts eighth grade at South next year.

Still, a few parents have responded by moving their children to another school, McCurdy said, while some others are complaining that their rights are being abridged.

Pauline Dial, whose fifth grader will attend South in another year, supports the move, citing skimpy clothing and clothing-label competition in the past.

"Most people who are against it probably haven't walked down the halls of a junior high in a while," she said.

No public school district in Idaho has had uniforms before, Boise school officials said. And this tranquil city, which has grown rapidly in size and diversity over the last several years, was unusual among cities its size — about 250,000 population — in not having any public school kids in uniforms, McCurdy said.

At South, where more than half of students qualify for free and reduced lunch, "a very unequal system" had developed, the principal said, noting a recent influx of immigrants from places like Bosnia, Africa and Mexico.

Uniforms were just one of many changes at South, she said, which had the lowest test scores in the district when she started there as principal four years ago, and no longer does.

David Brunsma, a sociologist at the University of Missouri, estimates that as many as a quarter of U.S. public elementary schools now have uniforms, a significant increase from the 1990s. Uniforms are making their strongest comeback, he says, in the upper grades.

Brunsma, editor of "School Uniforms: A Decade of Research and Debate" (Rowman & Littlefield Education, 2006), said there's no evidence that uniforms affect school attendance or performance, or things like crime or drug use.

As for why so many school officials are giving them a try, he speculated: "These kinds of policies, which don't actually have any effect, seem to be rooted largely in fear, and a desire to control a growing diversity of the student body."

As for my family, we ultimately found the school uniforms in Mexico to be practical.

Yes, we had to make sure they were always clean and ready for the coming school day, but I was spared debates with my daughter over what she would wear — and she avoided the bother of worrying about it. She knew what everyone else would have on.

Our kids, in fact, didn't seem to mind the uniforms at all. They couldn't wait to put on whatever was necessary to get onto the school playground. And uniforms helped them feel they fit in to a place with a foreign language and culture.

Even teachers wore versions of the uniform. At assemblies, the whole group looked like a giant gathering of bagpipers under the palms.