Exactly. Every culture has conformity standards, they just differ in the details. The reasoning largely reduces to "kids who stand out are 'distractions' and n

Exactly. Every culture has conformity standards, they just differ in the details. The reasoning largely reduces to "kids who stand out are 'distractions' and need to conform". It's not any different from rules in US schools about bare shoulders, pants vs. skirts (and length of skirt), buttons on shirts, etc...