The sibling relationship has been deemed the quintessential “love-hate relationship.” Sibling relationships have also been found to have both positive and negative impacts on the adjustment of youth. Unlike previous research, however, the present study examined the associations between siblings’ positive and negative body-related disclosures with relationship quality and body-esteem. Additionally, ordinal position, individual sex, and sibling sex composition were tested as moderators. Participants included 101 predominantly White and middle class adolescent sibling dyads (54 % female adolescents, with relatively equal sibling gender compositions). Older siblings were, on average, 16.46 (SD = 1.35) years old with younger siblings an average of 13.67 (SD = 1.56) years. Adolescents completed questionnaires and data were analyzed using Actor-Partner Interdependence Modeling, which focused on disclosure to and from dyad members. In general, sibling body-related disclosure was positive for the quality of the sibling relationship, regardless of the valance of disclosure. Also, adolescents’ body esteem was greater when adolescents reported disclosing (i.e., actor-effects) about positive or negative body issues to their siblings (particularly for females). Conversely, when adolescents received positive or negative body-related disclosures from their siblings (i.e., partner-effects), adolescents reported lower levels of body esteem (particularly for girls and younger siblings). Thus, the impact of body-related disclosure on adolescents’ feelings of body esteem appear to be associated more with whether they are the discloser or the one being disclosed to, while the impact on the quality of the relationship has simply more to do with whether or not they are generally disclosing to one another.
