Yes. The junior school my kids went to has uniform. The senior school was not. I realise that is not quite the same thing though. That said I have a mix my friends had a mix of uniform and non-uniform schools, and their kids also are mix. Across the board the opinion from parents and children is uniforms are old fashioned and need to go.

That said there are undoubtedly regional issues, and the areas I, my kids, my friends,, and their kids are in tend towards the middle-class and up, in terms of affluence. That would suggest a degree that affluence dictates behaviour, which is unfair because each school is different and the social background of the students doesn't always tell you if the school is a nice place or not.

The studies around behaviour and uniform have found that uniform does play a part sometimes, but usually there are other route causes and attacks related to the clothes the kids wore was just a symptom of other issues. So the lack of a uniform does not tell you if behaviour is going to be good or bad in a school. Schools have other tools that are more effective at handling behavioural issues, and some schools just have a harder time due to their location.

I worked at a school in Leeds a few years ago. They closed 3 other schools and brought together 3 different racial groups into a new single school. It was a nightmare at first but over time has improved to the point they no longer need a permanent police presence. This school has a uniform, but I highly doubt that had anything to do with their troubles.