Plenty of Machiavellians have bad parents, physically and emotionally abusive parents but there is a genetic component among other things.

Machiavellians_ Self-Made or Born That Way_

Being betrayed, used or abused by a Machiavellian is a painful experience that may leave their victims with ‘trust-issues’. But it will never leave the victim with more psychotic, mental and other baggage than the High Mach lives with all the time.