Schools aren't there just to fill students full of facts...
School Uniforms
Uniforms are worn in most aspects of life e.g. work, sports, recreational groups, etc. Uniforms can be highly stylized e.g. military, religious, team, etc, or socially conventional in appearance e.g. suits. The school uniform allows students to develop a common identity, to develop cohesion as a body, projects a "professional" image onto the community to which it belongs, and removes the appearance of social disparity. Schools aren't there just to fill students full of facts and figures, but also to prepare them for their future working lives and living within the society to which they will eventually contribute. I agree that, "an outfit doesn't help you learn" because, whether the "outfit" is a uniform or non-uniform, it is not a teaching aid. However the benefits of wearing a school uniform contribute to making a more conducive environment for educational purposes.