That single-sex schooling should be encouraged

1. The majority of people identify as heterosexual, which means that a same-sex schooling system eliminates the distraction of being attracted to someone else within the school environment for the majority of people. Since most people begin their first relationships with someone at the same school, same-sex schooling would have a big impact on the effects of these initial attractions. Being attracted to someone else while at school often has several common negative effects: it distracts from studies, it leads to increased mental focus on the subject of attraction rather than the self, and it encourages actions which are not in the best interest of one's self.

Each of these effects is undesirable. Distraction from studies often results in less mastery of the subject being studied. Being focused on thinking about someone else means we are spending more time thinking about what that person wants or enjoys, rather than what we ourselves want or enjoy. This can have a negative effect on self-esteem and self-confidence, as these traits are built on finding activities that fulfill us, and we cannot do that when we are focused on thinking about what we can do to fulfill others. This effect is especially detrimental in the age ranges when schooling traditionally takes place, as that is when we are primarily discovering and establishing who we are. In order to attract the interest of someone we are attracted to, we are often drawn to perform actions we may not otherwise consider - these may range from pretending to need help with something when we don't to doing something dangerous in order to "prove" to the other person that we're worth their time. These behaviors can often have negative ramifications both psychologically and physically - we can become the mockery of our classmates, and we can even hurt ourselves with the more daredevil behaviors.

All of the effects I have described are clearly negative. However, these are all effects of having a positive and successful attraction - the effects of being rejected romantically, and having to continue to be around that person on a regular basis can be far more damaging to the psyche, self-confidence and can even lead to depression and suicide in teenagers. With same-sex schooling, relationships would likely continue to take place, but they would take place outside of school and allow students more space to just be themselves within the school environment. Moving relationships outside of school for the majority of students would avoid the majority of these negative effects and would logically be a positive change for students both educationally and psychologically.

When schools are arranged with both genders, there is consistent opportunity for students to compare themselves against someone of the opposite group and find themselves lacking simply because of the gender they were born with. When students are only exposed to their own gender group, they cannot "write off" their lack of ability as due to the innate gender in difference in the person they are comparing themselves to. This means they are more likely to try to compete harder against others in a same-sex schooling environment, and thus more likely to push themselves more and potentially improve more as a result.

Sports make a great real world example. In professional sports, men and women are never included in the same teams - this is because of the same reason I already described: they have different physical capabilities, and cannot compete on the same levels. If you took a professional NBA team and a professional women's NBA team and asked them to play together seriously they would almost certainly refuse - that is because they accept their difference in playing levels and have no benefit in competing. This division in sports even happens in our current mixed-sex schools, especially for the more physical activities. Division in abilities affects more than sports, and same-sex schooling would benefit students in allowing them to focus on their strengths within their own group, instead of their comparative weaknesses to a disparate group.

Concerns and needs are different between genders. In our current system, we teach a little of both to everyone. In a same-sex schooling environment, we could tailor subjects more closely to the needs of the group. 

Teaching to the needs of a single gender group would also allow for focus on problems more prevalent within a particular gender - for example, health and psychological issues that tend to be more gender specific. If students learn better how to identify and avoid the issues most likely to impact them, they can better avoid being impacted by those negative issues. Logistically, this kind of specialization would be difficult in a mixed schooling environment. However, many of those logistical issues disappear in a same-sex schooling environment.

4. Same-sex schooling provides an opportunity to tailor programs in order to adapt and improve on traditional gender roles. Today, girls tend to gravitate towards more artistic and soft science skills, where boys are more attracted to the hard maths and sciences. This trend has been described as a problem in modern society, as it does not allow us to reap the full advantages of the skills inherent to our population.

In the current mixed-gender system, interactions between the gender groups would enforce the traditional gender roles. However, a same-sex system would be above those reinforcement, and would have more logistical means to tailor programs specific to emphasizing certain ideologies.
Gender roles are largely a product of our environment and the roles presented to children through toys, the media and the cultures surrounding them. Educational systems control the environment a child is exposed to through a large portion of the day, and can have a strong ability to emphasize an environment that encourages particular gender roles.

This idea is already being used today in some same-sex programs. Many existing programs focus on emphasizing traditional, religious views and teaching to the extremes of the traditional gender roles, leading to more conservative students compared to those who do not go through these programs.

In conclusion, same-sex schooling should be encouraged because it allows a number of strong benefits to students. It allows the majority of students to focus more on improving self-confidence through eliminating the potential distraction of attraction to the opposite gender. IT creates an even playing field, which encourages students to push themselves harder and, by extension, improve more. Studies can focus more on specific needs of the group, and students can get more emphasis on the area that are relevant to them. Same-sex schooling even provides potential benefits to the broader society, as it allows means to address concerns regarding traditional gender roles that validated by the current mixed sex schooling system.