I won't deny the three personality types exsist, I dont think our personalities always fall into place with birth order but I do think that the dynamic of our place in the family is effected by our birth order. Theirs good traits and bad traits.
The Firstborn Child: The Achiever
I think that a first wife who is older than the rest may fall into this catagory.
If you are a eldest/firstwife, you are probably a high achiever who seeks approval, dominates and is that perfectionist who uses up all of the oxygen in the room. As a sisterwife, you probably try to dominate your sibs. The problem is that when wife number two arrives, you will also experience a sense of loss. By losing your seat on the familial throne, you also lose the special place that singularity holds. All of the attention that was exclusively yours must now be shared by you and your sisterwife.
The Middle Child: The Peacemaker
If you are a secondwife/same age range, you are probably understanding, cooperative and flexible, yet competitive. You are concerned with fairness. In fact, as a second wife, you are likely to pick an intimate circle with in the family, the children to develope strong bonds with. It is here that you will find the attention when you are feeling like your are lacking it from your husband. You and your elder/ the firstwife will never excel at the same thing. But those wonderful social skills that you have learned as the secondwife negotiating and navigating within your family structure — can prepare you for anything.
The Youngest Child: The Life of the Party
If you’re the youngest and or third wife, your husband is already confident in his role as Patriarch, and therefore bumps aren't necessarily as bad. His attention is divided between you and your other sisterwives. Thus, you’ve learned how to win over the crowd with charm and likability.
As the youngest wife/third wife, you have more freedom than the other siblings and, in a sense, are more independent. As a third wife, you also have a lot in common with your oldest sibling, as both of you have been made to feel special and entitled. Your range of influence extends throughout your family, which supports you both emotionally and physically. Hence, you experience a sense of place and security.
I only have one wife but I people watch and from the interactions I've had with a few of the wonderful, beautiful plural families here at BF this is what I observed. Even the negative aspects don't seem as bad as they do reading them.