Students have the right to free expression in schools so long as that expression does not promote illegal activity and does not disrupt the classroom environment. This right was extended to students in the Supreme Court case of Tinker vs. Des Moines Independent Community School District (1969), after the school district punished students for wearing black arm bands as a symbol of protest against the Vietnam War. Opponents of school uniforms charge that clothes are the only method whereby students may silently express themselves in the classroom. School uniforms, therefore, infringe upon the student's right to voice their opinions should a need to express those opinions be felt.
Mandated school uniform requirements must include a clause that allows students to opt out of school uniforms on religious grounds. While this clause serves to protect student's religious freedoms, requiring school uniforms does not promote the inclusive society that the right to one's religion is meant to guarantee. Thus, requiring school uniforms creates a hostile environment of alienation and exclusion for observant religious students.
In Erik Erikson's "Eight Stages of Man," humans develop through a series of eight stages from birth to death. Among the childhood stages are the development of autonomy, initiative and identity, whereby children learn to make decisions for themselves and, in the process, formulate a personal sense of identity. A teenager, particularly, needs the freedom to explore the various aspects of her personality to get to know who she is and develop a sense of confidence. School uniforms limit the ability for students to develop an understanding of their identity with respect to their clothing. Clothing is also particularly functional in its expression of cultural and sub-cultural identity. Thus, the requirement of school uniforms directly infringes on a student's basic right to develop a sense of cultural identity and belonging to a specific cultural group.
Arguments against school uniforms on the basis of political and personal self-expression (not including religious expression) relate almost exclusively to middle and high school students, who are at ages where thinking about their place in the world outside of the context their parent's views begins to develop. Expression through clothing choice is just one form of self-expression and can be strongly influenced by peer pressure. School dress codes may be equally as stifling as uniform requirements by limiting jewelry and hairstyles. School uniforms offer students a chance to learn diversity as it relates to a person's personality instead of placing value on what clothes he wears.