Home / ACCES / Evidence-based Answers / School Achievement

School Achievement

Learn more by scrolling down the page or clicking the questions below.

  1. What does research find about single-sex versus coeducational schools?
  2. Do girls learn better in all-female math and science classes?
  3. What about the "boy crisis"? Can’t single-sex schools help struggling boys?
  4. Do girls and boys with certain personalities benefit from single-sex education?
  5. Do certain groups, such as children from low-income families, benefit more from single-sex education?
  6. Is there an age at which single-sex or coeducation is especially advantageous?

What does research find about single-sex versus coeducational schools? 

Research shows no difference in academic achievement between single-sex and coeducational schooling.

Decades of research from around the world demonstrates no  difference in academic performance between students in single-sex versus coeducational schools. The largest and most recent report was commissioned by the U.S. Department of Education, and concluded, “the results are equivocal.”1 The same finding – that gender grouping does not significantly affect academic performance – has emerged in large-scale studies from Canada,2 Great Britain,3Australia,4 and New Zealand.5 Often, single-sex schools look better at the outset, but once researchers correct for pre-existing differences in academic ability and socioeconomic status between students in the two types of schools, the effects melt away. British researchers Alan Smithers and Pamela Robinson titled their report “The Paradox of Single-sex Education” because so many people believe single-sex schools are better, but there is no scientific evidence to support the claim.

A truly rigorous comparison between single-sex and coeducational schools would require randomized student assignment and blind assessment, neither of which is feasible. Still, enough data are currently available to conclude that single-sex education is not the magic bullet for improving student achievement. Neither girls’ nor boys’ learning automatically benefits, sogiven its other social and financial costs, gender segregation is unjustifiable.

Parents and teachers should also beware of claims about striking successes at individual schools as reported on TV and in newspapers. Frequently, this “research” is highly biased – conducted by single-sex school advocates in a careless way that would not pass the standards of the U.S. Department of Education or scientific review. By contrast, a rigorous recent study of the Ann Richards School for Young Women Leaders in Austin, Texas, found that its girls performed no differently from students in coeducational schools after taking account of selection effects (e.g., girls admitted to the school were higher-scoring to begin with) and the influence of smart, motivated peers.6

Return to Top of Page

1 U.S. Department of Education, Office of Planning, Evaluation and Policy Development. (2005). Single-sex versus secondary schooling: A systematic review. Retrieved from

2 Thompson T., & Ungerleider C. (2004). Single-sex schooling: Final report. Canadian Centre for Knowledge Mobilisation. Retrieved from

3 Smithers A., & Robinson P. (2006). The paradox of single-sex and co-educational schooling. Buckingham: Carmichael Press. Retrieved from

4 Marsh H. W., & Rowe, K. J. (1996). The effects of single-sex and mixed-sex mathematics classes within a coeducational school: A reanalysis and comment. Australian Journal of Education, 40, 147-162.

5 Harker, R. (2000). Achievement, gender, and the single-sex/coed debate. British Journal of Sociology of Education, 21, 203-218.

6 Hayes, A. R., Pahlke, E. E., & Bigler, R. S. (in press). The efficacy of single-sex education: Testing for selection and peer quality effects. Sex Roles.

Do girls learn better in all-female math and science classes?

No. Girls do as well as boys in math and science in coeducational schools. Single-sex classes are not necessary and do not improve girls’ performance in these subjects.

Girls in coeducational schools have made impressive strides in all areas of math and science in recent decades, as gender stereotypes are declining among parents, teachers, and students themselves. Despite popular belief, there is little evidence that removing boys from the campus or classroom improves girls’ math and science skills.1

It is not the gender composition of a classroom that determines girls’ success in math and science but the quality of their instruction and resources, such as laboratories, and students’ own motivation and belief in hard work (as opposed to inborn talent) as the key to success. Teachers, parents, and peers of both genders can encourage or hinder such beliefs.

Of course, sexist attitudes still do undermine girls’ achievement in math and science in some schools. But the fact is, such views can turn up among principals, teachers, and students at both coeducational and single-sex schools.2 Parents should seek school environments that aim to optimize all students’ achievement, regardless of gender. Boys who are enthusiastic about math and science – and who support and encourage their female classmates’ efforts in these domains – are likely to bolster girls’ math and science achievement. Indeed, the best science and math academies in the U.S. are all coeducational.

Return to Top of Page

1 Organization for Economic Co-operation and Development and Program for International Student Assessment. (2009). Equally prepared for life? How 15-year-old boys and girls perform in school. Retrieved from

2 Lee, V. E., Marks, H. M., & Byrd, T. (1994). Sexism in single-sex and coeducational independent secondary school classrooms. Sociology of Education, 67, 92-120.

What about the "boy crisis"? Can’t single-sex schools help struggling boys? 

Single-sex classes are not especially beneficial for boys. Removing girls actually lowers boys’ achievement.

First, it is important to realize that, by many measures, girls do perform better in school. They score higher than  boys in reading and have largely caught up to boys in math and science. Girls consistently earn about 2/10ths of a point higher GPAs in high school than boys.1In addition, more males than females drop out of high school, although the good news is that dropout rates are declining for both sexes. After high school, fewer men than women are enrolling in college. Between 1970 and 2005, the gender composition has shifted to the extent that women now make up the majority (57%) of all undergraduate college students.

These gaps are important, but it is important to realize that they don’t hold for all groups. The real crisis is for low-income children (especially boys), particularly those from racial, ethnic, and language minority groups. The racial gaps are most apparent when it comes to high school graduation. Four-year completion rates for White boys and girls are 74% and 79% respectively. For Asian American students, the rates are 70 and 73%. But among Latino boys and Latina girls they are 49% and 58%, and for African American students are 48% and 59%.2

Unfortunately, single-sex education will not improve educational outcomes among poor and minority boys. In fact, if the existing data on gender and schooling find anything, it is that coeducation is clearly better for boys.3,4 Other research finds that both boys and girls benefit from a higher “dose” of girls in classroom, at both the elementary and high school levels.5 Similarly, a recent study of preschoolers found that boys performed better in co-ed classrooms, whereas girls did equally well in single-sex and co-ed classes.6

There is no question: Schools must to do a better job educating boys; however, there no evidence that single-sex schools are the way to meet this challenge. The answer to the “boy crisis” is not a segregated boot camp, but a supportive, literacy-rich environment, in which every child feels engaged and motivated to succeed. Rather than wasting resources on single-sex instruction, schools should invest in the higher quality instruction and staff – changes that are already proven to raise academic achievement among both boys and girls.

Return to Top of Page

1 U. S. Department of Education, Institute of Education Sciences, National Center for Education Statistics. (2005). High School Transcript Study (HSTS), various years, 1990-2005. Retrieved from

2 Green, J. P., &  Winters, M. A. (2006). Leaving boys behind: Public high school graduation rates.  Civic Report, No. 48. Retrieved from

3 Van de gaer,  E., Pustjens, H., Van Damme, H., & De Munter, A. (2004). Effects of single-sex versus co-educational classes and schools on gender differences in progress in language and mathematics achievement. British Journal of Sociology of Education, 25, 307-322.

4 Wong, K-C., Lam, R., & Ho, L-M. (2002). The effects of schooling on gender differences. British Educational Research Journal, 28, 827-843.

5 Lavy, V., & Schlosser, A. (2007). Mechanisms and impacts of gender peer effects at school. The National Bureau of Economic Research Working Paper no. 13292. Retrieved from

6 Moller, A. C., Forbes-Jones, E., Hightower, A. D., & Friedman, R. (2008). The developmental influence of sex composition in preschool classrooms: Boys fare worse in preschool classrooms with more boys. Early Childhood Research Quarterly, 23, 409-418.

Do girls and boys with certain personalities benefit from single-sex education?  

Although it’s often claimed that less-confident girls and less-disciplined boys fare better in single-sex schools, there’s no research to support this myth.

Any individual child who is struggling in one school may thrive when he or she switches to another. Our hope is that all children find the right environment to be successful; however, there is no evidence that a certain kind of girl – or a certain kind of boy – is more likely to excel in single-sex than co-educational schools. All children thrive in school environments in which they are well-understood, well-respected, well-supported, and expected to achieve at a high level. It is these qualities of teachers and peers – and not their gender – that shape children’s academic outcomes. Children who dislike school, who feel vulnerable or rejected, and who have strained relationships with their teachers are at risk for academic failure. In such cases, parents should take steps to address these issues and may even need to move their child to a different school. But it simply is not true that restricting enrollment to same-sex peers automatically solves the problems that put children at risk for academic failure.

Return to Top of Page

Do certain groups, such as children from low-income families, benefit more from single-sex education?  

No. Although there some outstanding single-sex schools that serve specific groups, they are not successful because of the single-sex environment, but because of many other advantages.

Some single-sex school advocates argue that gender segregation is especially beneficial for underprivileged students. Indeed, there are some shining examples of single-sex inner-city schools whose graduates have markedly high levels of academic achievement. These schools tend to have long school days, strict discipline, and high expectations for students’ academic and moral development; however, the advantages offered at such schools have very little to do with their single-sex structure, and much more to do with their dedicated teachers, unique resources, and strongly pro-academic culture. When similar advantages are present in co-educational charter schools, children are equally successful.

Return to Top of Page

Is there an age at which single-sex or coeducation is especially advantageous?  

Claims that single-sex schooling is especially useful in early elementary or middle school are not supported by evidence. Coeducational experiences are beneficial at every age.

Coeducational experiences can be beneficial at every age; however, there are two time periods when teachers’ encouragement of interactions between boys and girls may be particularly beneficial. The first is in preschool, when boys and girls tend to pull apart from each other. The second phase begins in pre-adolescence, when they begin to seek each other out. If boys and girls are removed from coeducational environments at these ages, they lose out on important opportunities to work together and influence each other. Because each gender tends to practice a narrower range of skills than both together, single-sex environments limit children’s opportunities and interaction styles. For instance, boys who spend most of their time with other boys learn skills for competing, but they may fail to learn how to communicate effectively;1 girls who spend the vast majority of their time with only girls miss out on physical and spatial experiences (important for math and science) or may ruminate excessively on their feelings and friendships, a risk factor for depression.

Studies of siblings have demonstrated the impact of cross-gender interactions on younger children’s interests.2 Sisters can promote their brothers’ verbal skills, whereas brothers can enhance sisters’ athletic and competitive skills. In general, gender differences grow larger when girls or boys interact only with their own gender, and differences grow smaller when they have many genuine opportunities to work or play together. Even the typical co-ed classroom may permit insufficient interaction, as boys and girls tend to segregate themselves, unless teachers direct them otherwise.

Some single-sex school advocates argue that early elementary school is a key age for gender segregation, because of developmental differences between boys and girls. Young boys are indeed more physically active than girls, although there are plenty of exceptions in every classroom. In fact, recent research has found that boys do better in preschool and early elementary classrooms with large percentages of female classmates.3 The growing number of single-sex elementary classes is likely to exacerbate, rather than reduce, existing academic gaps between boys and girls.

Other single-sex school advocates claim that adolescence is an optimal age for gender segregation , because it is assumed to minimize the flirting and showing off that emerge during these years; however, sexual interest is not eliminated in single-sex classrooms, and it is a fact of life in the workplace. Students can and should be taught to focus on academic work during school hours, just as they will be expected to focus on work within employment situations. At its best, coeducational schooling allows youths to develop an understanding of appropriate standards for interaction with other-sex individuals and to practice such skills in settings that parallel those they will face in the workplace.

Return to Top of Page

1 Martin, C. L., & Fabes, R. A. (2001). The stability and consequences of young children's same-sex peer interactions. Developmental Psychology, 37, 431-446.

2 Rust, J., Golombok, S., Hines, M., Johnston, K., Golding, J., et al. (2000). The role of brothers and sisters in the gender development of preschool children. Journal of Experimental Child Psychology, 77, 292-303.

3 Moller, A. C., Forbes-Jones E., Hightower, A. D., & Friedman, R. (2008) The developmental influence of sex composition in preschool classrooms: Boys fare worse in preschool classrooms with more boys. Early Childhood Research Quarterly, 23, 409-418.