“Who’s not doing well are poorer kids, kids from minority groups, but that really is not related to whether they’re female or male,” said one expert. Morry Gash/AP

Single-sex schools do not provide any social or educational benefits over coeducational programs within the public school system, according to a study by researchers at the University of Wisconsin, Madison. Their findings dispel assertions from proponents of same-sex schools that boys and girls learn differently and must therefore be separated to reach their full potential.

The team of psychologists examined all available research on single-sex education published within the past seven years, which included 184 studies comprising 1.6 million students from kindergarten to 12th grade in 21 different countries, and found no evidence to support proponents’ claims.

In their study, which appeared Monday in Psychological Bulletin, a journal published by the American Psychological Association, the psychologists said that students who attended single-sex schools weren’t any better off than peers who attended coed programs in terms of self-esteem or performance in STEM (science, technology, engineering and math) subjects.

Some education experts and parents have argued in favor of single-sex programs on the basis that boys are more dominating in classrooms and that separating kids by sex might enhance girls’ opportunities to excel in STEM subjects.

For example, Leonard Sax, founder and executive director of the National Association for Single Sex Public Education (NASSPE), has said that more graduates of all-girls schools will go on to major in hard sciences and math in college than those who graduate from coed schools.

But Janet Hyde, a professor of psychology and women’s studies and co-author of the study, said science doesn’t back that claim.

“There’s basically no difference,” she said. “What you see is that there’s one nondifference after another.”

Hyde said advocates of single-sex education often cite research studies that lack control groups, comparing, for example, a single-sex school within a privileged community with a coed school where students enjoy fewer advantages.

“The two best predictors of kids’ school success are the parents’ education and the family income,” Hyde said. “It’s just a meaningless comparison” if you pit single-sex schools against coed schools that differ on those measures. When you control for factors like affluence and parental education, the studies showing the advantages of single-sex classrooms “just aren’t supported by science,” she said.

Single-sex education in public schools came about with the advent of the No Child Left Behind Act. The U.S. Department of Education in 2006 rolled back a portion of Title IX, which bans sex discrimination in public education and guarantees equal federal funding for boys and girls across all education-related activities, in order to allow single-sex public schools and classrooms.

However, enrollment in single-sex education must be entirely voluntary, and school districts need to prove that there’s a compelling educational reason for creating a single-sex classroom or school.

More than 500 public schools in the U.S. offered single-sex classrooms or educational opportunities during the 2011–12 school year, with 116 of them entirely single-sex and the remainder with at least some coed opportunities alongside single-sex classes, according to NASSPE.

Opponents say single-sex classes and schools perpetuate gender stereotypes and that segregating kids by gender smacks of the kind of discrimination that — until Brown v. Board of Education struck down the practice in 1954 — allowed schools to segregate based on race.

The American Civil Liberties Union (ACLU), for example, has been investigating single-sex schools across the country and filing lawsuits against those it says promote gender stereotypes.

“Anything we organize along any variable, if we’re saying boys here, girls there, we’re telling kids that the way they learn is different,” said Diane Halpern, a psychology professor at Claremont McKenna College in California and dean of social sciences at the Minerva Schools at the Keck Graduate Institute, who has testified on behalf of the ACLU. “We are, in fact, enhancing sexual stereotyping.”

She added, “Who’s not doing well are poorer kids, kids from minority groups, but that really is not related to whether they’re female or male. There’s plenty of room for improvement in education, but this is not the right kind of improvement.”

Halpern and Hyde, along with several other social scientists, co-authored a 2011 article in the journal Science that said single-sex education advocates had used cherry-picked data and weak scientific evidence to present what the authors referred to as “pseudoscience.”

Hyde said that personal anecdotes from graduates of single-sex schools about their great experiences there can often flavor the dialogue about how helpful it actually is for students, but that “the adult world is coed.”

“From my point of view, segregation is a bad thing,” she said. “But if people found that girls really thrive in girls’ schools and girls’ classes, I’d say, well, let’s think about it. But it’s just not the case.”