It all boils down to upbringing.
I have seen parents heck care abt what their child does.
I have seen malay parents with headscarf and pious parents with
havoc children and totoos all over, and they seem bo chup abt the
kids.
Tsk, tsk, i pity them, if only they had proper upbrining in the
very first place.
That is why when people say "ur parents dont teach ah?" I seem to
find this true.
To be fair, these havoc kids are quite respectful to the elderly,
and usually we just a book by its cover. For example, like the one
you said about kids behaving in gangsterly manner while waiting to
play soccer, they are just being playful, and if ur friendly to
them, they will be friendly to u.