Unconsciously, through birth-order and being at different stages of cognitive development when events happen in the family, no two children are affected in the same way.
Some kids react in the opposite direction against over-controlling or tyrannical parents. They discover their best way to survive is defiance. And then they never stop defying and inadvertently rile everyone around them as adults.
The scape-goat personality evolves through trying to stop conflict between the parents by drawing it onto the self.
And some conditions are freak accidents of genes that the parents can neither understand nor accept.
I wouldn't call him the black sheep of the family, but I would call him the loser of the family. He takes after his own dad. (He's my mom's son but not my dad's.)