This came up in conversation with a friend today, and it's something i see all the time on here too...
Difficult teen causing lots of heartache and disruption at home, poor boundaries and tonnes of attitude - someone asks the parent what their childhood was like, what discipline/consequences/quality time they had, etc, because to be perfectly honest it is very very rare that a child with issues like that occurs out of the blue.
And every time, the parent says "I've got XX number of other children and they aren't like this, they were all raised exactly the same way!"
To me, this sounds like it's probably part of the problem. All kids are different, some have different needs to others, and applying a "one size fits all" approach to parenting is bound to have kids falling through the cracks with needs unmet.
My parents had two very different children, who they raised in two according styles, based on what worked for us. If i had been parented the way they parented my sister, i absolutely would have been defiant and angry and intransigent, and vice versa!