The influence of gender and birth order on adult sibling attachment relationships

The purpose of this study was to explore the influence of gender and birth order on attachment-anxiety and attachment-avoidance in sibling relationships during adulthood. Research has shown that of 85% of people grow up with at least one full biological sibling. At the same time there is a large gap in knowledge regarding sibling relationships in young and early adulthood. A total of 321 individuals between the ages of 18 and 40 participated in an online questionnaire. For each sibling, the participants provided the sibling's gender and age and responded to the Experiences in Close Relationships-Relationship Structure (ECR-RS), a 9-item questionnaire that measured the individual's attachment-anxiety and attachment-avoidance with that sibling for a total of 521 sibling relationships. The data was then analyzed through correlations, multiple regressions, and ANOVAs. The results of this study demonstrated that attachment-avoidance and attachment-anxiety were correlated with each other. The factors that influenced attachment-avoidance, however, were not the same as those which influenced attachment-anxiety. In terms of attachment-avoidance, birth rank and birth order of the participant were both found to significantly influence attachment-avoidance scores with older children reporting higher attachment-avoidance scores. The effect of birth order was also seen in the repeated measure of sibling position as the siblings were presented in the analyses in chronological order. In repeated measure ANOVAs for both gender and birth order with sibling positions, the sibling position was found to be a significant main effect. Gender was only found to be significant in interactions with birth order and there were no significant findings for attachment-anxiety. This study demonstrates the importance of sibling position in terms of attachment-avoidance and raises the question of what the primary influence may be for attachment-anxiety. Open-ended responses from the participants highlighted themes of loss, warmth, rivalry, and changes in sibling relationships over time. Results were discussed in terms of the importance of lifespan issues being significant in understanding sibling attachment in adulthood.