An attachment perspective on adult sibling relationships

This study investigated adult sibling relationships from an attachment perspective. A total of 817 adults (253 males; 564 females) ranging in age from 16 to 90 years completed a modified version of the WHO-TO measure of attachment strength (Hazan & Zeifman, 1994). This measure records multiple attachment figures, in order of importance, across four functions of attachment. One hundred and seventy four siblings of the participants also completed the measure as part of a larger sibling study. There were 29 brother dyads, 83 sister dyads and 62 brother-sister dyads. Results revealed that siblings have the potential to fulfil attachment-related functions, with 37% of the sample judged to be attached to a sibling. Females, and those not in romantic relationships reported stronger attachment to a sibling. Furthermore, sibling dyads were generally congruent in their perception of their relationship as an attachment bond. More than half of the sister-sister dyads (54%) agreed their relationship was an attachment bond, compared to 33% of brother-brother dyads and 24% of brother-sister dyads. Taken together, the findings support the applicability of attachment theory as a framework for investigating sibling relationships in adulthood.