One explanation for the fact that girls at single-sex schools are more likely to explore non-traditional subjects, then, might be that the single-sex classroom encourages girls to be daring, to try things that they might otherwise not try. Another explanation is that girls in the girls-only setting have more freedom to explore non-traditional subjects. Imagine that you're an 8th-grade girl, trying to decide what courses to sign up for in 9th grade. You're choosing between an advanced Spanish class and a computer programming class. You visit both classes. The Spanish class is very familiar: basically the same thing you've been doing for that past several years. The computer programming class at the coed high school, you notice, has 18 boys and one girl. The boys are loudly boasting about how much they know and how proficient they are at computer programming. Which class will you choose?

Most teenagers, female and male alike, will choose something they know they're good at rather than risking embarrassment -- and a bad grade on their transcript -- in a subject with which they have little experience. And, few girls want to be the only girl in a class of 20 boys. It's just not a real comfortable situation. So, you sign up for Spanish class.

But, if you have the opportunity to sit in on an all-girls computer programming class, you might come away with a very different attitude. In such a class, you'd see other girls whose background is similar to yours, and who are doing very well in the class. Isn't it more likely that you'd be willing to give it a try?

This example leads to another explanation for the fact that girls at single-sex schools are more likely to explore non-traditional courses. Girls at single-sex schools have more diverse role models of their own sex. In an all-girls school, the most amazing "computer geek" is a girl, the student council president is a girl, the top scorer on the math exam is always a girl, the best athletes are all girls, etc. That experience tells younger girls, it's OK to excel in math, sports, and girls can be really smart with computers, too.


Custom-tailored learning and instruction
Jean and Geoffrey Underwood have published a series of scholarly papers over the past 12 years, demonstrating the extraordinary advantages of single-sex classrooms for girls. In one of their studies, published in 1997, the Underwoods gave 31 pairs of 8-year-olds a computer-based language task. Children were randomly assigned either to girl-girl, girl-boy, or boy-boy pairs. Each child within a pair was matched with the other for reading ability. The Underwoods found a dramatic difference in story recall, depending on the gender composition of the pair. Boys in boy-boy pairs performed least well, while girls assigned to girl-girl pairs obtained the highest scores. The most striking finding, however, was that girls in girl-boy pairs performed almost as badly as the boys did. Just putting a girl with a boy degraded her performance by roughly 50% on this computer-based task. This effect was highly significant (p < 0.001). In other words: paring girls with boys does NOT help the boys, but it does HURT the girls. Similar findings have been reported by other researchers, for example Inzlicht & Ben Zeev, 2003. You can learn more about the Underwoods' studies, and about other scholarly papers demonstrating the unique effectiveness of single-sex classrooms for girls, by reading this page about teaching math and science to girls .

Teaching Literature
Recall again what you learned on our brain page: emotional activity is processed in completely different areas of the brain in older girls compared to older boys. In older girls, brain activity associated with emotion is localized primarily in the cerebral cortex, the same part of the brain involved in reasoning, language, and higher cognitive skills. So, the older girl is typically able to articulate her emotions fairly well, to explain what she is feeling and why. In boys, on the other hand, the locus of emotional control remains stuck in the amygdala, a phylogenetically "ancient" nucleus with no direct connections to the cerebral cortex. Older girls are usually comfortable sharing their feelings or imagining how others might feel in a particular situation. It's easy for them to link emotions with ideas, because those areas are linked in a girl's brain. Girls usually prefer books which focus on dyadic or triadic relationships (relationships among two or three individuals). "Girls tend to prefer books where they can be analytical about a character's motives and behaviors. Boys tend to prefer action," says Victoria Ehrhardt, an English teacher in Louis County, New York. "Boys and girls have different reading interests," agrees Judy Hayn, professor of education at Loyola University in Chicago. She adds that "Girls like stories about experiences that might happen over one summer and the emotional agonies that a character endures. Boys want stories with male protagonists that are exciting."

Role-playing exercises work well for girls. Consider having the girls create little skits, in which girls act out scenes from the book. Or, assign each girl to be one of the characters in the book, and have them discuss an issue "in character." For example, if you're teaching Are You There, God? It's Me, Margaret, one girl could be Margaret, another could be Margaret's mother, another girl could be Margaret's father, another could be Margaret's grandmother from Manhattan. They could then discuss the pros and cons of moving from Manhattan to New Jersey -- or the pros and cons of raising a girl in a particular religious faith vs. no religion at all. Each girl talks in the voice of the assigned character.

Inductive exercises are a variation on role-playing exercises. In an inductive exercise, you ask the girl to imagine herself in the role of a character in the story. For instance, if you're teaching Tolstoy's War and Peace, you might ask your student, "How would you feel if you were 17 years old and engaged to be married, and then your sweetheart announces that he's going away for a year -- just because his father told him to?" (the situation Natasha faces after accepting Andrey's proposal). Girls like a challenge in this exercise, so don't hesitate to do cross-gender inductive exercises. For example, from Steinbeck's East of Eden, you might ask: "How would you feel if you were Cal, and you discovered that your mother wasn't dead, but had abandoned you as a child? Would you want to go see her?"

Teaching Math
Best practices for teaching math differ fundamentally for girls and boys. Recall what you learned on the navigation section of our brain page: navigational tasks are handled by completely different areas of the brain in girls and boys. In girls, navigational tasks are assigned to the cerebral cortex, the same general section of the brain which is responsible for language. In boys, the same tasks are handled by the hippocampus, an ancient nucleus buried deep in the brain, devoid of any direct connections to the cortex.

These anatomical differences have major implications for teaching mathematical topics, especially geometry, algebra, and number theory. For girls, you want to keep it real and keep it relevant. Fibonacci numbers are a great way to introduce number theory to girls, for example. Recall that a Fibonacci series is formed by adding two numbers to yield a third number. The best-known Fibonacci series is: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89 . . . Ask your girls to bring in any of the following: artichokes, sunflowers, pineapples, pinecones, delphiniums, black-eyed susans, field daisies, African daisies, and Michaelmas daisies. Start with the flowers. (We start with flowers not because flowers are "feminine" but because it's easier to count the number of petals on a daisy than it is to count the number of rows of bracts on a pinecone.) Count the number of petals. You'll find that the number of petals is almost always a number in the Fibonacci series: 8 petals for delphiniums, 13 for double delphiniums, 21 for black-eyed susans, 34 for field daisies, 55 for African daisies and Michaelmas daisies.

Then you can move on to the artichokes, sunflowers, pinecones, and pineapples. These are more complicated. In these, you're studying the number of rows rather than the number of petals (or seeds or bracts). The number of rows counted vertically or obliquely will, again, be a number in the Fibonacci series. Be sure to read Fascinating Fibonacci by Trudi Hammel Garland, from which these examples are taken.

Learning style
Girls and boys differ fundamentally in the learning style they feel most comfortable with. Girls tend to look on the teacher as an ally. Given a little encouragement, they will welcome the teacher's help. A girl-friendly classroom is a safe, comfortable, welcoming place. Forget hard plastic chairs: put in a sofa and some comfortable bean bags. Let the girls address their teacher by her (or his) first name. The teacher should never yell or shout at a girl.

Girls will naturally break up in groups of three and four to work on problems. Let them. Minimize assignments which require working alone. If you're assigning class presentations, let two girls give a joint presentation. The format of one student giving a presentation to an entire class doesn't work as well (for girls) as two students giving a joint presentation to a smaller group.

Some of the biggest difference in how girls and boys learn derives from the fact that girls mature differently than boys do. If you've read about the biologically-programmed differences in the brains of girls and boys, then you already know about some of these differences in brain development. In single-sex schools, teachers are (or should be) free to choose materials that fit the interests of their students. In coed schools, the girls are often held back or held down to the abilities and interests of the boys.

Greater autonomy, especially in heterosexual relationships
Let's start with one of the most basic facts about single-sex education at the middle school and high school level: girls in single-sex schools are much less likely to experience unwanted pregnancies than are girls at coed schools. What's the explanation for that fact? The most common explanation put forward is that girls at single-sex schools are less likely to be involved in heterosexual relationships than are girls at coed schools. But is that a true statement?

Katherine Sanders and Neville Bruce tested the hypothesis that girls at single-sex schools have fewer heterosexual relationships than do girls at coed schools. To their surprise, they found no evidence to support this hypothesis. They acknowledged that they "had expected that single-sex schooling might inhibit incidence of romances, at least during the school years. But this view was supported by only two of eight possible comparisons and the trend in four of the comparisons was in the opposite direction" (i.e. students at single-sex schools were more likely to be involved in romantic relationships). "Thus, it would seem that students from single-sex schools are not noticeably thwarted by any lack of opportunity or experience in the single-sex school system from experiencing romantic episodes, either at school or later in their early university years."

Source: Neville Bruce and Katherine Sanders, "Incidence and duration of romantic attraction in students progressing from secondary to tertiary education," Journal of Biosocial Sciences, volume 33, pages 173-184, 2002.

All right. If girls at single-sex schools are involved in just as many heterosexual relationships as girls at coed schools, how come girls at single-sex schools are so much less likely to experience an unwanted pregnancy? Studies demonstrate that when 15- and 16-year-olds at coed schools form romantic relationships, they do so less on the basis of individual characteristics and more on the basis of where the teenager stands in the clique. The most popular boy in the group goes out with the most popular girl, the second most popular boy goes out with the second most popular girl, and on down the line, with the least popular boy paired with the least popular girl. Sexual relationships in this age group, far from involving intimate personal connection, instead appear to be more of an exercise in role-playing.

Sources:

Anthony Pellegrini, "Bullying, victimization, and sexual harassment during the transition to middle school," Educational Psychologist, volume 37, number 3, pages 151-163, 2002; also Bukowski, Sipploa, & Newcomb, "Variations in patterns of attraction to same-and other-sex peers during early adolescence," Developmental Psychology, volume 36, pages 147-154, 2000.

At a coed school, your boyfriend is part of your circle of friends, the people you hang out with. Your boyfriend is part of who you are. Your boyfriend's friends are likely to be your friends too. You all do stuff together, go places together. If your boyfriend dumps you, your whole social network is put at risk. So, if the other girls in your group are having sex with their boyfriends, it's hard for you to say no. Saying no to your boyfriend has the potential not only to jeopardize your relationship with your boyfriend, it jeopardizes your entire social standing at school.

It should come as no surprise, then, that teenage sex and unwanted teenage pregnancy are much more common at coed schools than at single-sex schools. The most obvious and undisputed advantage of single-sex education is the dramatically lower risk of getting pregnant in middle school or high school. To understand how important that single benefit is, you need to understand how common teenage pregnancy continues to be. Teenage pregnancy hasn't been in the news much in recent years, because the rate of teenage pregnancy is no longer rising. But the United States continues to have the highest rate of teenage pregnancy and the highest rate of teenage births in the industrialized world. And, the percentage of young girls having intercourse is rising. What's really happened over the past 20 years is that more young girls are having sex, but a smaller percentage of young girls are having babies as a result. According to the National Campaign to Prevent Teen Pregnancy, the number of girls under 15 who have had intercourse increased from 11 percent to 19 percent between 1991 and 2000. In other words, almost one out of every five 14-year-old girls nationwide now has had intercourse. Nearly four in 10 young women become pregnant at least once before they reach the age of 20, and 80% of those pregnancies are unintended.

At a single-sex school, though, even if you do have a boyfriend, your social network at school is likely to be separate from your boyfriend's group of friends. So, it's easier to say no. You have more autonomy over your sexual decision-making. It's easier to contemplate life without the boyfriend.

Bottom line: girls at single-sex schools have just as many heterosexual relationships as girls at coed schools. But girls in single-sex schools are more in control, have more autonomy in those relationships, and -- as one result -- are much less likely to experience an unwanted pregnancy.