Table of Contents

About the Author

Reader Feedback

Chapter 5



The underlying thesis of the birth order factor is that a large amount of the personality characteristics that define us are determined by the family constellation (20) in which we grow up.

Certain predictable types of relationships prevail between siblings, between spouses, and between parents and their children; and the common denominator that cuts across all of these relationships is the influence of birth order.

NOTE: The PREFACE acquaints you with the structure and function of the family genogram, information that you may want to refer back to as you explore the following diagrams of typical sibling constellations.




For starters, we can have two brothers, or a brother and a sister, or two sisters or more, or several siblings of the same type; or we can be an only child. Also, we can have a twin sibling, or be a middle or oldest (or youngest) sibling, or we can have lost a sibling. When married, our spouse can be older than us or younger than us, and can share our particular sibling position with us (or not).

As parents, if we have two or three children, one of them is more than likely going to share our exact sibling position, just as another child may share the other parent's exact sibling position.

Our particular sibling rank and order helps set the tone for happens to us in life. We carry the influences of our particular sibling rank and order into marriage and into subsequent parent-child relationships. We also carry it into the world with us as members of a team or workplace group, or even as a member of a corporate board of directors or military unit -- yes, even the U.S. Congress.

NOTE: Certain rank and order relationships tend to be more compatible than others.

THE IDEAL: The marriage between an older brother of a younger sister and a younger sister of an older brother can be considered ideal. Both have had years of experience dealing with the other person's sibling posture, and both know pretty much what to expect in that regard. The graphic below illustrates this sibling rank and posture in a marriage:


The above situation is the [opposite] of what happens when an older brother of brothers marries a sister with only sisters. Neither one of the spouses has had intimate, on-going experience growing up with members of the opposite sex. The following diagram illustrates this scenario:



Now consider the marriage between two oldest siblings. When there is conflict in this kind of relationship, it often relates to the fact that both are used to being in the oldest postion, and neither wants to give in to the other. The spouses are both used to making decisions and being in charge, which is OK so long as things are calm between them:



The opposite is true in marriages between two youngest siblings. When marital discord erupts, it more often than not has to do with the struggle to maintain the pampered position of 'youngest' where nobody wants to make decisions or be in charge:


Generally speaking, then, the more experience one has had growing up with siblings of both genders and of differing ages, younger and older, the better prepared one is for the twists and turns of life's relationship complexities.

Sometimes only children can be the least well-prepared for life's relationship complexities. They are, however, fearless in many ways and are to be reckoned with in political and other powerful circles when they can function independently.




The very same kinds of control issues affect parent-child relationships.

EXAMPLE: A couple marries and has two children. Father is the oldest brother of a younger sister and Mother is his IDEAL match as the younger sister of an older brother. Their two children include first a boy and then a girl. Harmony in this family will be at its optimal (IDEAL) level in terms of the parents' individual abilities to understand their two children. Father knows what it is like for his son to have to deal with a younger sister, and his tolerance for their sibling interactions will be quite high. Mother, too, sympathizes with the problems of being a youngest daughter with no sisters and only a big brother to play with:


Things might be quite different had the son turned out to be the youngest of the two children, especially if Father is one of those dominant, 'take charge' 'big brother' types. He wouldn't be nearly so sympathetic with his youngest son's sibling struggles because he had no role model available to him growing up for how a youngest son is supposed to act with an older sister.

With Mother, the same would be true.

EXAMPLE: Let's say that the same IDEAL marriage between oldest and youngest sibling types produces three children instead of two. Then let's say that the first born is a female, the next a male, and the last born another female:


If there is to be trouble between parents and children in the family, it is most likely to occur between one or the other parents and the oldest girl. Why? In this case, neither parent has had experience with the position expectations for the role of first born daughter. The parents' own sibling-rank experiences significantly interfere with their ability to understand this oldest daughter.

All of the above is further COMPOUNDED when you take into consideration each parent's past experiences, especially the emotional tone of that experience in his or her own family of origin.


EXAMPLE: For the sake of argument, let's say that Father's Father was also a first born and only male in the family, a prized position in the family. First born males in that family for generations have been revered and honored in a great display of tradition; such that those males grow up cared for and treated like kings, but are also thought to be 'unmanly' if they show any sign of weakness emotionally.

That person becomes a father in the same tradition and doesn't know what in the world to do with a son that comes out the family 'baby':



EXAMPLE: What if, instead, a [Mother's] experience growing up included having an oldest brother who was considered the 'whimp' of the family and generally a problem child. The Mother's growing up years as youngest sister in that family were focused on trying to undo all the awfulness that this oldest brother in the family perpetrated.

Having a first born son, in her case, would be disastrous. Unless she has somehow grown up resolved and forgiving of all those 1st born brotherly things, she is going to struggle with the fear that this same scenario will repeat in her family. Her every gesture and behavior towards this first born son of hers will be highly affected by her own familial circumstances.

Take a look:


Ingrained reactions to certain sibling positions rather than just to the persons that happen to occupy those sibling position are at the root of many instances of family disharmony.




Certain 'rules' governing sibling relationship patterns must be borne in mind when trying to understand birth order influences in a family.

THE ABSOLUTE MIDDLE SIBLING: Contrary to public mythology, the absolute middle sibling is not the most maligned sibling position. This is the sibling with older and younger brothers and also older and younger sisters.

This person, unlike many others, is prepared for all types of relationships in life.


NOTE: A janitor in the workplace who grew up smack-dab in the middle of a constellation of 17 children close in age may actually be the most adaptable employee of all.


SIBLING SUBGROUPINGS: Very large sibling constellations tend to split into subgroups, mainly because of age differences between siblings. Typically there will be an oldest subgroup, and usually a younger subgroup.

Each subgroup, in turn, has its own 'oldest' and 'youngest' siblings and the two subgroups function relatively autonomously of each other over the course of their lives.

The larger the family, the more potential subgroups there will be.



The vertical dotted line in the above diagram illustrates how age splits the seven siblings into two subgroups based on the age gap between the 28-and 22-year olds.

Subgroup one includes an older brother of a younger brother. The younger brother's sibling position is that of a younger brother of an older brother. Those in subgroup two do not affect the 1st group's sibling positions.

In subgroup two, the baby boy's sibling position is that of a youngest brother of four older sisters. The 22-year old female is an oldest sister of younger sisters and a brother.

The 20-year old's 'absolute middle' position remains with all the benefits of having both older and younger brothers and sisters; however, her predominate sibling position personality in this case is that of a younger sister of an older sister with younger sisters and a brother.

When siblings are separated by six or more years they form emotionally separate subgroupings in a family.



ONLY CHILDREN: Only children have no sibling position since they have no siblings.

The only child's contacts are with parents. Only children learn how males and females interact and relate to one another by observing their parents interact. They have no practice with other children.

Indeed, they mostly know how to handle adults and they often look and act like little adults themselves. They also often marry other only children and still more often produce a single off-spring of their own.

When an only child marries and produces a large family, it usually suggests that their experience of being an only child growing up was a negative one. Still, it doesn't make them a very adaptable parent from a sibling personality perspective, therefore parent-child issues and even marital issues will most likely ensue.



TWIN SIBLINGS: Twins comprise a small percent of all births. They are always a [twosome] in the family that produces them, even though the family tries to handle twins as if they were ordinary siblings, which they are not. The family generally even appoints one of the twins to be the 'older' and one to be the 'younger' depending upon who came out first. This happens even in the case of identical twins.

If there are other siblings older and/or younger than the twins, the twins take on the sibling position and personality that a [single person] would in their sibling position. So if the twins are first borns in the family, with younger siblings, then BOTH occupy a first-born sibling position. The male twin is a first-born brother of a younger brother and sisters; and the female twin is a first-born sister of a younger brother and sisters.



STEP AND HALF-SIBLINGS: In the case of step and half-siblings, one needs to consider the individual's position in his or her original (family of origin) to determine their correct birth order. Also to be considered with step and half-siblings is the effect of the [loss] of any previous family members, which will have an effect on their future relationships with others.



The above MOTHER married and had two sons by her first husband, whom she then divorced in 2008. She brought her two sons with her into that 2nd marriage and shortly thereafter had another child by her new husband. The boys retain their sibling posture as older and younger brothers, and the baby daughter grows up as an only child even though the boys live in the same household with her.

RULE: The older children are when the step or half-sibling situation arises, the less likely they will be altered in their basic sibling personality.


ADOPTED CHILDREN: Adopted children take on the sibling position of the adopted family in which they find themselves, although this assumes infant adoptions. Older children who are later adopted retain their original sibling position from their family of origin.

The family in which one has lived the longest imparts the greatest influence.

In the EXAMPLE below, the youngest female child (a youngest sister of five older brothers) was adopted at the age of six by a much older childless couple. The 6-year old's basic sibling posture, therefore, is that of a youngest sister of numerous older brothers but with 'quasi-only' personality characteristics that result from having grown to adulthood as an only child in the adoptive family.


As you can see, sibling positions can actually be very complex and sometimes hard to accurately determine without help.



(1) Children who grow up and become parents themselves tend, through identification with their own father and mother, to repeat those relationship patterns with their own children.

(2) If a parent treats any of his or her own children somehow differentially, it is likely to happen in favor of the child who shares the identical sibling position as the parent. This holds whether the differential treatment is positive or negative.

(3) When there are more than six years between children in a family, the one that is born first (or last) is considered a 'quasi-only child' even though there may be other siblings. This would be the case in a family of three children that, six years later, produces a fourth offspring. This fourth child is a 'quasi-only' child.

Such a child has siblings that share the same set of parents, but an age space of six or more years separates them from their siblings.

Furthermore, one can be a quasi-only child of the OLDEST SORT and also a quasi-only child of the YOUNGEST SORT. Quasi-only children of the 'youngest sort' tend to have a higher level of functioning overall while those of the 'oldest sort' tend to have been much more caught up in the parental marriage for one reason or another, and are more anxious in general.

You can read more about this influence in APPENDIX 5.




(4) Small age differences between siblings bind them together emotionally while large age differences separate them emotionally.

(5) Immediately adjacent siblings have greater influence over each other than non-adjacent siblings do. Also, losses of siblings (i.e. through death) impact immediately adjacent siblings the most.

(7) Just as age differences separate siblings by emotional distance, age also inserts emotional distance between between parents and their children. Older parents, for example, have generally less intimate relationships with their children than do parents much closer in age to their children.

(8) Similarly, the greater the difference in age between spouses, the greater the emotional distance in the marriage.




Sibling position impacts one's relationship experiences far beyond the realm of the family.

EXAMPLE: 'Best friendships' tend to arise between people who share the same sex and sibling rank in their respective families. Thus, two females who are both youngest sisters (or even quasi-only children of the youngest sort) are going to have far more in common than two females, one of which is an oldest.

In essence, then, we empathize and better understand those who share our particular view of the world; a view that is, in large part, cultivated in childhood as siblings in our family of origin.

Youngest or younger siblings are often more laid back and laizze-faire than older, more responsible siblings who have grown up with parent-like responsibilities for their younger siblings.

Adult 'caretaker' types are typically oldest siblings who were used to taking care of everyone else in the family, especially in situations where a parent died or deserted the family. This leaves a great deal of responsibility in the hands of the oldest sibling at an early age, and that caretaking mindset goes with them into the world -- into jobs and most certainly into marriages.

The workplace, in fact, is a common platform for acting out one's particular sibling postures.

Sisters with only sisters adjust less well in the work place than do sisters who also have experience with brothers. Sisters with only sisters work very well with women but they have to work much harder to keep their composure in the face of conflicts with male superiors or equals. This is because they had minimal life experiences with males during their formative years.

Men, on the other hand, who have strong ties to their sisters tend to look to women for support in the work place, and they tend to include them in all phases of responsibility in the workplace. That said, if their relationship history with sisters was negative, then that also affects how they deal with women in the workplace.

Men who are only children tend to run an organization in much the same way that things were run in their families of origin -- they pretty much get their way -- and they aren't well-equipped to deal with the range of sibling personalities in the workplace. An only child is not a good choice as a college president, for example, where the personality complexities of a university require a more adaptable person that works well with older and younger brothers and older and younger sisters as university employees.

Most people with whom we have serious conflicts are those who trigger challenges to our sibling personality.


EXAMPLE: Let's say we had a smothering mother who followed us around, constantly wanting to know what we were doing and injecting directions about how to do this and that every time we turned around. Then let's say we meet up with the same smothering 'type' in the world. You can bet that our reaction to that woman (workplace or not) will not be positive. Replace the smothering mother with a domineering, bossy, oldest sister type -- then imagine the result.

These kinds of conflicts happen at work, on committees, on boards of directors, in non-profits, in university environments...even on the New York Stock Enchange and in Congress and the Military. No workplace is free of sibling position influences among employees and professional associates.

The effects of birth order run deep.



I once did a sibling position study of the entire intensive care nursing staff in the ICU of a large hospital. The study happened because I was a consultant there at the time and the ICU Director was constantly complaining about how hard it was to work with her ICU nursing staff. It turned out that her ENTIRE STAFF of highly qualified nurses were mostly first borns with some only- children who gravited to autonomous positions such as in an ICU where one nurse has full responsibility for one patient at a time. Just knowing this fact helped the Director to keep her sense of humor about the goings-on of her unit. Luckily, she was also an oldest sister of a younger sister with the emotional strength that goes with that sibling position.

I did a similar study of all 150 faculty and staff members of a local university athletics department. 98% of the people employed in the department at the time were youngest siblings. Youngest siblings, as noted earlier, tend to be more fun-loving and laizze-faire. They respond to leadership directives less seriously and more playfully, and they are generally not that easy to deal with as a collective.

Another one of my sibling studies centered around a project where 16 men were selected to sail a replica of a Colonial ship from France back to the United States, much like it was done in colonial days. The crew hadn't even set sail yet and mutiny was about to erupt, so the ship's doctor called me in to assess the situation. It turned out that a personnel committee had hired the ship's captain first and then the others; and the captain turned out to be a youngest male while all the rest of the mates were oldest or even only-child males. This did not make for a cohesive group under this captain's leadership and for good reason: he did not have the same strength of personality of his oldest/only child crew members. The project did not go as planned, falling far short of its goal when an entirely new crew had to be hired to bring the ship back to its original port of call.



References for Chapter 5:

(20) Walter Toman, Family Constellation

(21) R. D. Laing, Politics of the Family


[Go to Chapter 6]

[Return to main APPENDIX]