Employing Walter Toman's (1976) sibling profiles, Bowen considered that sibling position could provide useful information in understanding the roles individuals tend to take in relationships.

For example, Toman's profiles describe eldest children as more likely to take on responsibility and leadership, with younger siblings more comfortable being dependent and allowing others to make decisions.  Middle children are described as having more flexibility to shift between responsibility and dependence and 'only' children are seen as being responsible, and having greater access to the adult world.

Bowen noted that these generalised traits are not universally applicable and that it is possible for a younger sibling to become the 'functional eldest'.

Bowen was especially interested in which sibling position in a family is most vulnerable to triangling with parents.  It may be that a parent identifies strongly with a child in the same sibling position as their own, or that a previous cross generational triangle (eg. an eldest child aligned with a grandparent against a parent) may be repeated.  If one sibling in the previous generation suffered a serious illness or died, it is more likely that the child of the present generation in the same sibling position will be viewed as more vulnerable and therefore more likely to detour tensions from the parental dyad.

Helping the client understand and think beyond the limitations of their own sibling position and role is a goal of Bowenian family of origin work.

Clients are encouraged to consider how assumptions about relationships are fuelled by their sibling role experience.

As with other aspects of Bowen's theory, the impact of gender and ethnicity on sibling role is not considered.  For example, there is no exploration of how a family's ethnicity influences which birth order position and which gender is more valued, or how the gender of any sibling position tends to influence whether the role is primarily relational (female), or task oriented (male).