If you are the scapegoat in the family you may be having a hard time finding any information about this role. I've been looking for years and it has been quite difficult. Fortunately, a local poet, Rick Belden, has written a book of poetry on the scapegoat role and is allowing previews of it on his website.
Scapegoat's Cross: Poems about Finding and Claiming the Lost Man Within is beautiful and heartfelt and I encourage you to take a look. The samples are free and there is no obligation, nothing to sign up for. Rick is very generous in sharing his work, perhaps too generous! If you like what you see, buy the entire manuscript. It is worth every penny and we need more poets in this world of ours.