His whole psychology fascinates me.
It's no news that Charles doesn't like him. I don't know about the others, but of course he'll show a different side of himself to his family. I'm sure when he went for a ride with his mother in her last years, he didn't ask her if she 'took it up the arse', or explain how he'd trousered X million pounds from a dodgy Arab businessman. Probably, to Princess Anne he's been just the boastful, arrogant, not-very-bright younger brother. The various Fergie scandals, though, and the Epstein scandal, must have made an impact on her.
Edward - I can't see them, of all the siblings, hitting it off, with Edward's early interest in the arts and much less gung-ho demeanour. I'm only surmising - but that's all we can do! I know someone who worked with Edward in Australia (or NZ....sorry, can't remember which) on a 'year out' activity and she said he was lovely. Looking at him, I really can't imagine he's cut from the same cloth as Andrew. Much more like a less intelligent Charles (disclaimer: yes, I know I'm only guessing here - but guessing from long interest and observation). He strikes me as not over-bright but well-meaning and harmless.
Yes, I can see all kinds of consequences in the siblings' characters which have resulted from their different childhood experiences. Charles's lack of maternal contact early on, the mismatch of his personality and his schooling, the failure to be the macho, uncomplicated character his father perhaps wanted. Anne - like Charles would have been brought up in a different way and a different time to her younger siblings and both would have been influenced by a more old-fashioned sense of duty and perhaps morality.
I read that, by the time Andrew and Edward were born, the Queen was employing a much more lenient and permissive nanny, so perhaps that, combined with her own favouritism, meant that Andrew lacked the early discipline he needed. But it doesn't explain the difference from Edward.
I've been in education most of my career and honestly, I've encountered boys like Andrew from a range of backgrounds. He might well have had some form of SEND, but I bet he was pretty unteachable, wouldn't be told, was unfazed by authority, had no empathy or concern for others and to whom the concept of personal shame was completely alien. What I'm saying is, you don't need to be royal to be that sort of person and being privileged and even spoiled doesn't (for me, anyway) explain his awful character.