There was a recent study done that showed that all adults have some type of trauma in their upbringing so some degree. Obviously it is considerably worse for some than for others.
I've met adults who've had seriously traumatic upbringings who are so damaged it's heart breaking and gut wrenching. They stories they tell make me want to cry and hug them and wish they could have had better. The saddest part is, they're fundamentally left to their own devices as adults to deal with their damage and try to heal on their own.
These damaged individuals are just sent off into the world in hopes they'll just be ok or do well enough as adults. Often they fail because their trauma is too much for them to cope with every day life. Most end up abusing those around them because they don't know any other way to function. Some parent neglectfully because they would rather be too lenient than too disciplinary.
Some are lucky and break the cycle.