Sibling interaction is an often overlooked aspect of family functioning. Individual development and many family behavior patterns may be attributed to autonomous activities within the sibling sub‐system.
A number of phenomena in which siblings have profound influence upon one another are explored. Siblings collude and align with each other, at times help each other resist the powerful vertical influences of parents. Other sibling systems serve to enmesh the youngsters even more with parents. Important sib‐behavior patterns include: the death or departure of siblings; the interplay between the sibling sub‐system and the parenting system; and the roles that “well” siblings play vis‐à‐vis their “sick” siblings during family crises. The sibling relationship is seen as a life‐long process, highly influential throughout the life cycle.
Understanding of sibling sub‐system structure and dynamics can lead to more flexible therapeutic interventions. Direct work with siblings provides the therapist with more options and greater leverage in producing change for all siblings, as well as for other family members.