These benefits outweigh the lack of expressiveness students may experience. Therefore, schools should have student dress codes.
The first benefit to having a student dress code is that students will no longer waste time trying to decide what to wear so that they can look "cool." Their dress will have already been decided by the dress code. The time and effort that students put into selecting their outfit can instead become precious additional minutes in an already busy day. A friend of mine who attended a public middle school, but went to a private high school where uniforms were required, said that she welcomed the change. Instead of taking an hour to put together an outfit, it only took her five minutes, and she was able to spend the extra time in the morning eating breakfast and finishing up homework.
Another benefit to having a student dress code is that it helps to eliminate socioeconomic and cultural differences among students. For example, children who come from richer families will typically dress better than students who come from poorer families, which can cause poorer students to feel embarrassed and insecure. With a student dress code, students will, for the most part, be wearing the same attire. This makes socioeconomic status less apparent, helping poorer students not feel self-conscious.
Having a student dress code has been shown to be effective in making schools safer. In schools that are in bad neighborhoods, theft can be common. I once taught at a school in the Bronx where it wasn't uncommon for students to fight other students to steal their clothes, tennis shoes, or jewelry. At