From the mouths of babes?

There's a saying that goes something like that, and it usually means that the unvarnished truth is being told.
But you don't normally expect it from a teenager.  Why am I wittering on about this you are possibly wondering?
Well, yesterday there was a fight at the school I work at, in the Maths block.  (I found out later that there had been more than the one fight.)  But it is this particular one I am going to mull over.  I didn't even see it happening, yet the whole of the year involved were buzzing about it.  It was a comment afterwards from another year 8 boy that made me think.
Due to damage being done if they are left open, the toilets in the Maths block are kept locked. The key is kept in the office, which is next to my "office", (it's a store cupboard.)
If students need to use the toilet they have to ask for the key, and return it.  One of the students is very chatty, and he mentioned the fight, and did I know what had happened to the boys involved. He then said "Well, Bert Boggins is a Pikey, so he thinks that he can do whatever he wants."  (Obviously Bert Boggins is not the student's real name.)  But I thought, yes, how true. "Pikeys" do think that they can do what they want when they want, and the rules are for everybody else. There are quite a few at our school, due to where we are, and they are a very disruptive element in the school.  The particular student is a nightmare, but he also turns on the charm when he wants to, which makes it harder for the teachers to deal with him, because they never know if it is Dr Jekyll Bert Boggins they have to deal with or Mr Hyde Bert Boggins.
Ah! Had I better tell you what a pikey is, or do you know?
A Pikey is a slang term for a traveller, that is a member of the travelling community, the males of which tend to be arrogant and to steamroller people into their way of thinking. And actually one of the other Pikey students was also involved in a fight yesterday as well I have since learnt.