Birth Order and Gender As Moderators of the Association between Affiliate Stigma and Sibling Relationships Among Adult Siblings of Individuals with Developmental Disabilities in South Korea

Background and Purpose:

Stigma affects not only people with developmental disabilities (DD) but also their families, particularly siblings, who are more susceptible to experiencing affiliate stigma. It is crucial to recognize that sibling relationships are lifelong, and as such, the sense of affiliate stigma can accumulate over time. The affiliate stigma experienced by siblings of people with DD impacts the sibling relationships. The existing body of research indicates that non-disabled siblings frequently encounter societal discrimination, experience feelings of resentment and frustration towards their siblings, and have less emotional closeness in their relationships compared to typical sibling dyads. Moreover, birth order and gender may modify the association between affiliate stigma and sibling relationships. Studies have found that younger siblings of individuals with DD often have lower self-control, leading to both higher intimacy and more conflict in their sibling relationships. Siblings of the same gender typically experience more conflict but also feel a stronger sense of identity with each other, which intensifies at younger ages. If one sibling has a DD, especially if they are young and of the same gender, the relationship can deteriorate due to affiliate stigma. Sibling relationships are crucial for both psychosocial adjustment and as a source of care and support for individuals with DD. Although previous studies indicated that affiliate stigma is a determinant of sibling relationships, little is known this pathway might change based on birth order and gender. Therefore, this study aims to examine the moderating effect of birth order and gender on the relationship between affiliate stigma and sibling relationships.

Methods:

Participants were recruited using convenience sampling through Seoul Support Center for Family with Disability. Between August and October 2020, 200 adult siblings of individuals with DD completed in the survey, and data from 156 were analyzed.

The survey included four main components: 22 items from the Affiliate Stigma Scale (Chang et al., 2015), 48 items from the Lifespan Siblings Relationship Scale (Riggio, 2000), and the moderating variables, birth order and gender. Control variables included age, education level, religion, parental attachment, and disability type of individuals with DD. To examine the moderating effects of birth order and gender on the relationship between affiliate stigma and sibling relationships, data were analyzed using SPSS 24.0 and the PROCESS macro version 4.2 (model 2).

Results:

The analysis revealed that affiliate stigma predicted lower sibling relationships (B=−.235, p<.05), and this relation was moderated by birth order(B=−.379, p<.05) but not gender(B=−.019, p>.05). However, in conditional effects models, the negative association between affiliate stigma and sibling relationships strengthened significantly when the non-disabled sibling was younger than the disabled sibling, and when both siblings were of the same gender.

Conclusion and implications:

These findings underscore the detrimental impact of affiliate stigma on sibling relationships, with this effect significantly moderated by birth order and gender. Specifically, the negative influence of affiliate stigma is more pronounced among later-born siblings of the same gender as individuals with developmental disabilities, highlighting the need for tailored intervention strategies that consider sibling dynamics and demographic characteristics.