BIRTH-ORDER AND AGE-DIFFERENCES IN EARLY SIBLING ROLES

Seventy-six two-children families were assigned to one of three cohorts that differed in the second born's age at an initial home visit (5, 11, or 17 months); the families were seen again 6 months later, when the baby was 11, 17, or 23 months. Mothers rated each child on nine sibling role qualities (i.e., functions or feelings) that reflect aspects of sibling roles. Children were also videotaped interacting in structured situations that were later coded for specific functions. First and second borns were seen to fulfill different roles; e.g., mothers rated firstborns lower than second borns on identification, but higher on help. The differences between the two children on some aspects of sibling roles (e.g., identification) did not change with the children's ages. Yet other aspects (e.g., help) became increasingly similar, and such changes were attributable to the baby's development. Children's behaviour in the structured situations also changed over the early sibling relationship, but, although some changes were attributable to the baby growing older, others were attributable to the older sibling's, or to both children's, development. The discussion focuses on possible sources of birth order and age differences in early sibling roles.