In a recent study done by researchers at the University of Houston, claims about the positive effects of school uniforms were put to the test. In their findings, researchers were able to determine that school uniforms did not help students perform better in the classroom, but attendance did increase among students and the retention rate for teachers at schools that adopted uniforms also increased. Therefore, it seems that requiring uniforms to be worn by students may have some positive effects, but increased test scores and grades are not among them.

Source: Freakonomics Blog