We note with trepidation the push for all-day kindergarten in Utah. The Legislature has OK'd all-day instruction to more schools, but we have grave doubts about the merits of the idea.

Nationwide, the percentage of full-day programs has grown from about 25 percent in 1984 to 60 percent in 2001, and likely more by now. The trend, if anything, is accelerating. Half-day kindergarten is so unpopular in northern New Jersey that many families hold their kids out of the public schools or send them to private full-day kindergarten programs. A glance at news reports shows that in recent weeks pressure has mounted for such programs in Michigan, North Dakota, Illinois, Ohio, Minnesota, Connecticut, Washington, Nebraska and Kansas.

Longer classes include more instruction, which is meant to give kids a boost in reading, math and other academic skills. Advocates haul out various studies indicating that all-day kindergarten helps children, especially those from lower-income families, learn more and faster.

We're skeptical. Research going back seven decades suggests that any advantage of early education disappears later on. Earlier this year, for example, the Goldwater Institute in Arizona found that any boost kids received from preschool and kindergarten programs had vanished by the fifth grade.

"This report demonstrates that all-day kindergarten is not an education reform strategy that policymakers can hang their hats on," said Darcy Olsen, president of the institute. "All-day 'k' delivers short-term benefits at best."

Other commentators have noted that the real results won't be measurable for decades -- when kids have grown up. By that time, it's too late to correct any problems, or to recover the billions spent.

Of course, it's all about money. Usually backers of all-day kindergarten try to be subtle about this. But the New York Times let the cat out of the bag a decade ago. It quoted education "experts" as saying all-day school for tots "makes economic sense ... because it allows working parents to save on child-care expenses."

"It's absolutely absurd that kindergarten is half-day in any district at this point," Rutgers professor Lesley Mandel Morrow told the Times. "The public sector has got to come into sync with economic realities."

In short, "all-day 'k' " is government day-care.

A good case can be made that children of kindergarten age are better served by playing or being with their families than they are sitting in a classroom. Many a parent will attest to the negative emotional impact of detaching a child too early.

Indeed, a backlash has been building. A story last month in the Boston Globe Magazine pointed out that dragging children to school too soon may actually hurt their development. Some grow bored. Others, when asked to do things their brains aren't ready for, get discouraged or acquire the tag "slow learner," which becomes a self-fulfilling prophecy.

Each child is different, researcher Maryanne Wolf said. The ability to read, for instance, depends on the integration of complex functions in different parts of the brain, and no school can change the biology.

Of course learning is important for young children. But the best place to learn is at home. As the Globe reported, "Study after study shows the best thing parents can do for their children is give them a nurturing, rich, vibrant environment, reading to them often and exposing them to lots of language in organic ways."

Sadly, Utah families have, overall, been doing a mediocre job at that, according to a study by the Reach Out and Read National Center in Boston. Utah ranks 36th among the states and District of Columbia in the percentage of parents who read to their kids every day.

It should be noted that the study was based on research from 2003, before state officials stepped up efforts to persuade more parents to get with it. Still, it indicates how easy it is for parents to do more for their children than all-day kindergarten can.

Why are we even thinking about virtually turning our kids over to the government at such a charming, vulnerable age and shove them into a social maelstrom for which they cannot possibly be preparedfi And why is academic achievement now emphasized at the same level at which many adults over 40 experienced only a gentle socializationfi

In fact, plenty of successful people never attended kindergarten at all but started school in first grade.

Little children have many more years of school ahead of them. Their brains and tender psyches ought to be given room to develop before being subjected to the pressure cooker of academic achievement and the jungle of social competition. Why spend millions to push developing round pegs into square holes before their timefi It's a form of child abuse.

Parents should think carefully before getting their children involved in this latest educational fad. The truth is what every parent has always thought: Kids need their parents.

Unfortunately, too many parents need a baby sitter.

Do you agree?