One of the questions I am often asked is does birth order influence your behavioral style?
Well, based on the research we have performed, birth order does not influence your natural behavior. When I say natural behavior, I mean the core “hard-wired” behavior which is based on genetics and then shaped into you up to 3 years old. The natural behavior changes very little throughout your life. Understanding the influence of natural behavior is important because it is very influential on your life motivations and hence how you make decisions.
In some families you see the eldest child being the more dominant, independent, and risk taker type with the youngest being the more engaging and harmonious type. Then, in another family with the same number of children it is exactly the reverse. There is no trend either way. Further, you cannot predict which child will be more successful. The same is true of single children families. The only child could have any type of behavioral style across the full spectrum – dominant, harmonious, risk takers and creative. Generally, when there are 2 or 3 children in the family they will be very different. However, when there are 4 or more children then you may have 2 who are quite similar, yet they will still be unique.
What I would say is that the birth order could nevertheless influence some aspects of the longer term personality development which takes place after the age of 3 years. This will be because as children are born circumstances or environments in that family change and the opportunities are different for each of them. In some cases, the presence or influence of one or both parents may differ. For instance, I have seen a bankruptcy in a family have a great impact on the 2 eldest born because they had a lot taken away from them whereas the youngest 2 children hardly lived through it. Similarly, the death or serious illness of a parent could have a different influence on the eldest and youngest children. Or even a divorce. Also, there can be other factors such as the way in which one parent connects with one of the children e.g., the father with the eldest daughter or mother with the youngest son. So, what I am saying is that these types of factors are all an influence on personality and the birth order could matter. The influences on the personality development are much more specific situation driven.
Overall, I would say it is difficult to make definitive predictions of personality based on birth order. This is particularly because evidence shows the core natural behaviors which are foundational to personality development do not relate to birth order. It is difficult to say that the eldest child will always behave a certain way, then the middle children and the youngest child will also behave a certain way. The make-up of every family and the circumstances each lives through are different. That is as far as it goes. Therefore, there are no rules which generally apply.