Abstract

Sibling relationships are a unique and critical context through which we can investigate early adolescent development and well-being. Positive sibling relationship qualities (e.g., warmth) are implicated in many facets of adolescents’ lives; for example, positive relationships promote positive self-worth (Noel et al., 2018) and fewer internalizing and externalizing symptoms (e.g., Dirks et al., 2015). An important, yet understudied, relational feature reflects the degree to which early adolescents feel that they can trust their sibling. Specifically, the extent to which they can rely on the behaviours or promises made by a sibling can have important implications for the sibling relationship and adolescent well-being. As such, the present three studies investigated the role of sibling trust and its value within the context of the sibling relationship and for adaptive and maladaptive adjustment. Study 1 reports on a new self-report measure of sibling trust that addressed the methodological limitations of previous measures of trust and examined its association with sibling relationship satisfaction. Findings revealed a two-factor structure based on reliability trust and trust honesty, which were each positively predictive of sibling relationship satisfaction. Regarding birth order, the effect of trust honesty was stronger for older siblings than younger siblings. Study 2 examined the predictive value of sibling trust on adolescent general self-worth in a cross-cultural sample from Canada and Colombia. Results indicated that sibling trust was positively predictive of general self-worth, social competence, and academic competence. Further, the effect of sibling trust on social competence was stronger for boys than girls, whereas no significant cultural differences were observed. Study 3 investigated the protective function of sibling trust on adolescent perceptions of depressed affect and the intolerance of uncertainty over a two-month period. Reliability trust and trust honesty differentially predicted the stability of depressed affect, such that high reliability trust weakened the association while high trust honesty strengthened it. Together, findings are discussed relation to established theoretical frameworks regarding the multidimensionality of trust (Rotenberg, 2010) and relationships theory (Hinde, 1979). Generally, these results supported the relative value of trust within the sibling relationship and its importance for maintaining a satisfactory relationship and individual well-being.