I am not so sure I would say that any one order is more malaligned than another. We generally tend to think that the middle child is the one who receives the least attention, while the oldest is most responsible, dependeable, etc. However, raising 4 children has taught me otherwise. My oldest daughter (16) is the one who has given me the most problems so far and is also the one we have to stay on all of the time. She is very much a follower and because of this, tends to not think on her own. In contrast, my son (14) is a leader and gives us less problems. He tends to stray away from the negative, is very intelligent, atuned to other people's feelings, and well adjusted. The other two children (7 and 1) are a bit too young yet, but I can see different traits already that suggest each has already developed a unique sense of self.
Based on this, I am inclined to believe that birth order does not make one child more dysfunctional than another. In think personality and temperament play more of a role in this than anything.
Also, many cousins that I have (who are the middle child) are more successful than the older or youngest child in the same family. However, I am the oldest in my family and am the most successful one.
Again, this makes me question the whole birth order phenomena. Then again, that's just my opinion.