Bowen theory incorporates the research of psychologist Walter Toman as a foundation for its concept of sibling position. Bowen observed the impact of sibling position on development and behavior in his family research. However, he found Toman's work so thorough and consistent with his ideas that he incorporated it into his theory. The basic idea is that people who grow up in the same sibling position predictably have important common characteristics. For example, oldest children tend to gravitate to leadership positions and youngest children often prefer to be followers. The characteristics of one position are not "better" than those of another position, but are complementary. For example, a boss who is an oldest child may work unusually well with a first assistant who is a youngest child. Youngest children may like to be in charge, but their leadership style typically differs from an oldest's style.

Toman's research showed that spouses' sibling positions affect the chance of their divorcing. For example, if an older brother of a younger sister marries a younger sister of an older brother, less chance of a divorce exists than if an older brother of a brother marries an older sister of a sister. The sibling or rank positions are complementary in the first case and each spouse is familiar with living with someone of the opposite sex. In the second case, however, the rank positions are not complementary and neither spouse grew up with a member of the opposite sex. An older brother of a brother and an older sister of a sister are prone to battle over who is in charge; two youngest children are prone to struggle over who gets to lean on whom.

People in the same sibling position, of course, exhibit marked differences in functioning. The concept of differentiation can explain some of the differences. For example, rather than being comfortable with responsibility and leadership, an oldest child who is anxiously focused on may grow up to be markedly indecisive and highly reactive to expectations. Consequently, his younger brother may become a "functional oldest," filling a void in the family system. He is the chronologically younger child, but develops more characteristics of an oldest child than his older brother. A youngest child who is anxiously focused on may become an unusually helpless and demanding person. In contrast, two mature youngest children may cooperate extremely effectively in a marriage and be at very low risk for a divorce.

Middle children exhibit the functional characteristics of two sibling positions. For example, if a girl has an older brother and a younger sister, she usually has some of the characteristics of both a younger sister of a brother and an older sister of a sister. The sibling positions of a person's parents are also important to consider. An oldest child whose parents are both youngests encounters a different set of parental expectations than an oldest child whose parents are both oldests.

Source:

http://www.thebowencenter.org/