Here are some relevant differences. According to a 2001 study², women use the right and left hemispheres of the brain to process language; men use only the left hemisphere. In general men are more likely to use one area of the brain for a given activity; women are more likely to use more of the brain. Studies show that women respond to directions that include data about what they will see and hear; men prefer abstract directions³ . Girls’ brains develop through adolescence so that girls are better able to discuss their feelings; boys’ brains do not. Research is revealing major physiological differences in the brains of even pre-adolescent boys and girls ⁴ . For example, seven-year-old girls hear better than boys ⁵.

These physical differences lead to differences in the way boys and girls learn. Teachers need to encourage girls, while boys need a reality check. Direct challenging works well with boys and they tend to respond to clear boundaries. Emotional activity is processed in a completely different part of the brain in older girls compared with older boys. It has been suggested that girls respond more innately to literature and that they more easily make links between ideas and emotions. In stories, girls tend to respond to nuances of character, boys to action ⁶. Role-playing exercises allowing a student to explore character work particularly well for girls. Inductive exercises allowing girls to act hypothetically also work well. There is evidence that boys respond more to structured lessons, finite tasks, and perhaps to the more abstract. Girls tend to respond more readily to group work and team work. One fascinating study suggests that under certain circumstances stress has a beneficial effect on male learning, but that it can impair the learning of a female, and that this characteristic is wired in the male brain from before birth⁷.

Most children learn better in a single-sex environment
On average, children in single-sex education outperform children of comparative ability in co-ed contexts. In a 20-year Australian study of 270,000 students, Ken Rowe found that both boys and girls performed between 15 and 22 percentile points higher on standardised tests when they attended single-sex schools.⁸  The National Foundation for Educational Research in England⁹  found that, even after controlling for student ability and other background factors, boys and girls performed significantly better academically in single-sex schools than in co-ed schools. Students in Jamaica attending single-sex schools outperformed students in co-ed schools in almost every subject tested.¹⁰  A 1997 study by Jean and Geoffrey Underwood showed that girl-girl pairings performed best on tasks, and that girl-boy pairings tended to depress the achievement of the girls involved.¹¹ 

Boys and girls experience the benefits of schooling in different ways. British studies suggest that females more than males benefit academically from single-sex education: they participate more in class, develop higher self esteem, score higher in aptitude tests, are more likely to choose sciences and other male domains at tertiary level, and are more successful in careers. Research suggests that boys dominate the classroom in a co-ed environment. Boys can behave more loudly. Some research has shown that girls receive fewer encouraging comments than boys in co-ed environments. Studies by Cornelius Riordan suggest that children from underprivileged backgrounds are the greatest beneficiaries of single-sex schooling.¹²  The message of all this research is simple: there are no differences in what girls and boys can learn, but here are big differences in the best way to teach them.

Single-sex education meets the needs of boys better
Boys and girls have different needs and education which respects personal differences must take this into account. On a practical level, the intuitively directed and affectively oriented styles of learning which suit most girls are not always compatible with the more structured and practical approaches which appeal to boys. Single-sex schooling allows teachers to tailor their teaching style to the boys and facilitates a more rounded educational experience. In a co-ed school, boys can opt out of curriculum areas where they would be out-performed.

Furthermore, there is evidence that mixed classrooms can discriminate against either boys and girls depending on the subject, the gender of the teacher, the teacher’s methodologies, and the prevailing culture in the school. Some schools have now started running single-sex classrooms in English and other humanities subjects to improve the performance of boys. The pilot study that demonstrated improved performance of boys in this context has been known as the Cotswold Experiment.¹³ 

Single-sex education meets the needs of girls better
Single-sex education has clear benefits for girls. In the first place, it often gives them expanded educational opportunities by allowing them to pursue non-traditional disciplines for girls such as mathematics or science. Single-sex schooling also offers more opportunities to girls to exercise leadership. When girls and boys are in the same classroom, the boys tend to dominate and overshadow equally talented girls.

On an emotional level, single-sex education puts less pressure on girls, especially in adolescence. At that age, girls are more prone than boys to suffer from low self esteem. It is difficult to manage this issue in a co-ed climate when boys dominate in the classroom and when they receive more recognition, allowance for misbehaviour and encouragement.

Single-sex education makes greater provision for gender role modeling
The shortage of male teachers in the primary classroom is a concern in many countries. In the first six years of school, many boys in co-ed schools seldom encounter a male teacher. Because children imitate those they admire, it is common sense to ensure that boys and girls find in their teachers truly admirable role models. The example of professionalism, values and consistently positive behaviour is most important. But there are other aspects of example that are gender-specific. A boy learns what it means to be a man from his father, but this is reinforced if there are other admirable men in his life. This is also true for girls and their female teachers.

Single-sex schooling allows boys and girls to mature at their own pace
Girls mature earlier than boys: they are better behaved, more diligent and more sensible and they find it easier to relate to the adult world. For all these reasons, it is often argued that girls exert a civilising influence on boys. Whilst this may be true in some situation, the converse is also true: boys can uncivilise girls. When adolescent girls and boys study together, there is much evidence that a proportion will end up distracted from their work.

Single-sex schooling is often criticised for reinforcing negative images of masculinity. Unfortunately this can even happen in co-ed schools. The problem is not solved by bringing girls and boys together, but by vigilantly managing the culture in a school and sub-groups in the school.

Single-sex schooling does not handicap children socially
There is no evidence that children who have attended co-ed schools enter adult relationships that are more stable or fulfilling with the opposite sex. Assertions that children from co-ed backgrounds are better prepared for adult life seem to be flawed. There is a higher rate of unplanned pregnancies (and by implication, of terminated pregnancies) for girls in co-ed schools. One study has shown that students from single-sex schooling are not noticeably thwarted in the development of relationships with the opposite sex either at school or later at university.¹⁴

Coeducation can allow socialising to complicate intellectual development. Of course a positive school culture and the superior training of teachers can work against this. But it is difficult to protect impressionable young people from the images of precocious intimacy that saturate the media. Since emotional attraction and physical attraction works first of all at the level of physical proximity, there seems a strong argument to separate a teenager’s academic world from his or her social world. In a coeducational secondary classroom the lines between social life and school can become blurred. Single-sex education allows children to think about things “other than their hormones”.

Single-sex schooling makes it easier to be a good parent
Single-sex schools also provide parents with an opportunity to manage more effectively the social development of their children, particularly in the early years. It makes it easier for them to impart education about sexual matters in a way consistent with their values. Of course when parents choose to send their children to single-sex schools they will need to have much more initiative in providing for the social development of their children. They should set up many opportunities for boys to mix with girls in a family setting during childhood, well before they turn 14 or 15. It is very late to be starting to talk with a child about these issues once he or she has reached mid secondary school.

An undeniable problem for all families is the gulf between home life and a teenager’s social world. Children must feel they can bring their friends home. Coeducational schooling does little to help because it creates a social environment which is totally beyond the parents’ knowledge and largely outside their control. Unhappily when youth culture becomes divorced from family life, a certain percentage of children are sure to end up badly damaged.