It’s a multitude of things but as a parent of a primary age private school kid and a governor at a state school there are some glaring differences that I believe make a difference. And there are many financial/legal/governance reasons why some of those things do/can happen in a private school not a state.
Public speaking/performing constantly, in class, in shows, in assemblies, in soloist concerts, debating etc.. you just don’t get to hide.
Requirement to shake hands, look teacher in eye and say confidently good morning/good evening every single day (it’s so easy and so effective)
Discipline - they are responsible from yr 2/3 normally for everything, not their parents. Kit/homework/timetables/knowing what team they’re in and when/getting to extra activities/music lessons themselves on time etc... no excuses no parent excuses either. It’s tough at first but we all get used to it. And they all contribute to “houses” discipline affects not just them but their “team” through lost points, missing events etc...
Competitive sport, auditioning for plays/shows, singing comps, poetry comps, drawing comps... they all find their thing and they get to win at it.
Drop Off.... literally! Past year 2 you almost never see parents hanging around with kids in the playground it’s expected that you drop and go... our pre-prep has the same if you choose too with teachers to head them in... my yr 4 walks home, they let them out at 4pm (from yr 4) and they are off. The look and comments of horror from parent governors that the kids would be distraught if parents couldn’t stay until the bell in the morning went, when I suggested it at a meeting reviewing parking issues was amazing to me.
As above my experience (two private schools due to move) is that neither the school or the parents (on the whole) mollycoddle them during school hours, authority is to be respected and most parents respect the school and trust them to do what’s right. And this ironically creates kids with enough confidence to question said authority too, they just do it with respect most of the time so works both ways.
Entitlement- yes... these kids are privileged there’s no denying they’re not, but I rarely see the stereotypical type mentioned here. They usually have successful, confident, hard working parents and that rubs off. They also have the type of parent (and a school who feels comfortable doing the same) who is much more likely to tell them to get a grip and get on with it if they falter than a parent who would allow them not to try. Not saying that’s better or worse just my observation. If you’re told you can do it just try/keep trying enough usually you do do it.
Much less health and safety rubbish... So they get to really play/run/snowball fight/wander far/take risks and that builds confidence in itself.
Not sure how replicable this is at home but it does work and the school rather than parents tend to drive it. Unexpectedly I have found the more you pay the less you even consider interfering unless it’s obviously a serious health/safeguarding etc.. risk to your child. Children grow in the sun, not in the shade of their parents!