It's both, in a cyclical feedback loop. The wealthy teach their kids to be entitled, greedy, selfish, sociopaths... and extreme wealth and power corrupts the vast majority of humans — being surrounded by employees, fanboys, and other yes men who worship you 24/7 — is likely to create entitled, greedy, selfish, sociopathic behaviors; extreme wealth and power create the mental illness of narcissism, and that mental illness is passed to their children.
Couple that with an economic system that explicitly rewards narcissistic behavior with wealth and power, and you end up in a civilization crippled by a mental illness epidemic, actively spread by the propaganda of the richest mentally ill.