Do parents need to be at their children’s schools?

American parents show up at their children’s schools. A lot. Nearly nine out of 10 attended at least one PTA or other school meeting in the 2011-12 school year, according to data recently released by the Department of Education’s National Household Education Surveys Program.

Six out of 10 participated in at least one school fundraiser. American parents stay up late baking cookies for bake sales, and they leave work early for football games. It’s a remarkable investment of time and heart.

Yet over the past couple of years, as I traveled around the world visiting countries with higher-performing education systems while researching my book The Smartest Kids in the World, I noticed something odd. I hardly saw parents at schools at all.

“My daughters’ school does not ask me or anyone else to do anything,” says Susanne Strömberg, a journalist and mother of twin daughters in public elementary school in Finland, the country where 15-year-olds rank No. 1 in the world in science and No. 2 in reading. She sounds almost wistful as she considers the absence of such solicitations. “No money donations, never!”

Finland, like most countries, spends less per student on education than the U.S., but parents were not expected to top off the budget. Other than attending two short parent-teacher conferences a year, Strömberg was expected to leave school to the teachers and fundraising to the government.

In South Korea, where parents are obsessed with their children’s educations to a sometimes unhealthy degree, I saw parents driving their kids to after-school tutoring academies, jamming the streets of Seoul late into the night. But I did not see many parents at school.

Parents are involved in education in these other countries, but they are involved differently. They are more involved at home. And that, it turns out, might be one secret to their success.

In a 2009 study of parenting in 13 countries and regions, parents who volunteered in school extracurricular activities had children who performed worse in reading, on average, than parents who did not volunteer, even after controlling for children’s backgrounds. Out of 13 very different places, there were only two (Denmark and New Zealand) in which parental volunteering had any positive effect on reading, and it was small.

How could this be? Weren’t the parents who volunteered in the school community showing their children how much they valued education? The data are mystifying, but other research within the U.S. has revealed the same dynamic: Volunteering in school and attending school events seems to have little effect on how much kids learn.

One possible explanation is that volunteering parents were more active precisely because their children were struggling at school. And it’s possible their kids would be doing even worse if the parents had not gotten involved.

Or it might be that parents who spent their limited time and energy coaching football and organizing school auctions simply had less time and energy for the other kinds of activities that help kids learn.

In that same international study, parents who routinely read to their young children raised teenagers who performed significantly better on a test of critical thinking in reading years later, even after controlling for the effects of socioeconomic background. Likewise, parents who discussed movies, books and the news with their kids had teenagers who not only performed better in reading but reported enjoying reading more overall.

In fact, if parents simply read for pleasure at home, on their own, their children were more likely to enjoy reading, too. That pattern held fast across very different countries and income levels. Kids noticed what parents valued, and it mattered more than what parents said.

American parents have grown to think of schools as social hubs, places where they can see friends and help one another. That is a beautiful tradition, one that school leaders could channel to do great things. If principals lean on American parents for spending money and staff-morale boosters, they should make it clear that this kind of investment is secondary. First of all, parents should make sure to read to their kids, read for themselves and talk to their children at dinner about the world around them. If and only if they have done all these things and still, miraculously. have energy left over should they wash cars and set up a tent next to the soccer field.

These days, American parents get blamed for many of America’s education problems. In surveys, adults cite a lack of parental involvement as a major cause of our mediocre outcomes. But whatever else we are doing wrong, American parents are in fact showing up at our kids’ schools more often than we have in the past 25 years, according to a 2012 MetLife survey of American teachers and parents. Maybe the trouble is that we are showing up at the wrong place.