A systematic review and meta-analysis of the associations between interparental and sibling relationships: Positive or negative?

According to family systems theory, a family is regarded as an organized whole and relations within this system are interconnected. However, it is not clear to date whether the interparental and the sibling relationship are associated and, if such an association exists, whether it is positive or negative. Previous findings on the associations between the interparental and sibling relationships are inconsistent and there is as yet no pertinent review or meta-analysis. Therefore, this systematic review and meta-analysis set out (1) to aggregate previous studies investigating the links between the interparental and sibling relationships and (2) to examine potential moderators in this link. Based on 47 studies reporting 234 effect sizes (N = 29,746 from six nations; 6–12 years; 49% boys), meta-analytic results suggest a small positive correlation between interparental and sibling relationship quality (r = .14). Only the percentage of male children in the sample moderated this effect. Sex composition of sibling dyad and source of publication affected whether positive or negative associations were found. The findings support a growing consensus that family relations do not function in isolation, but are mutually interdependent, which should be considered in clinical practice.

“Brothers in Arms”: Secondary Traumatization and Sibling Relationship Quality Among Siblings of Combat Veterans

The aversive impact of exposure to combat and posttraumatic stress disorder (PTSD) on family members has been examined mainly among veterans’ partners and offspring. No study has examined secondary traumatization in veterans’ siblings and the role of relationship quality in these links. The present study aimed to assess secondary PTSD symptoms (PTSS) and general distress among siblings of combat veterans, and the role of sibling relationship quality in the association between veterans’ exposure to combat and PTSS and sibling secondary PTSS. A sample of 106 adult dyads of Israeli combat veterans and their closest in age siblings responded to self-report questionnaires in a cross-sectional study design. The rates of sibling secondary PTSS and general distress were relatively low. However, veterans’ exposure to combat and PTSS were positively related to siblings’ secondary PTSS. Importantly, veterans’ PTSS mediated the association between veterans’ exposure to combat and siblings’ secondary PTSS, only among sibling dyads with high levels of warmth and low levels of conflict in their relationship. Furthermore, the inclusion of siblings general distress contributed to heightened sibling secondary PTSS, but only the warmth dimension moderated the link between veterans’ PTSS and siblings’ secondary PTSS. Findings suggest that veterans’ PTSS is implicated in their siblings’ secondary PTSS. Veterans’ PTSS might also serve as a possible mechanism for the links between exposure to combat and siblings’ secondary PTSS. Moreover, relationship quality with a sibling veteran might take a toll in the form of siblings’ secondary PTSS following veteran military service.

Normative and nonnormative pattern in achievement of developmental tasks: Sibling relationship quality and life satisfaction during emerging adulthood

The aims of the present study were to investigate whether twins and siblings close in age (1) present a normative pattern in the achievement of residential, working, and economic autonomy (the older sibling assumes a more adult role earlier than the younger, or twins assume an adult role at the same time); (2) differ in sibling relationship quality; and whether the normativity is linked (3) to the quality of sibling relationship and (4) to life satisfaction. A cross-sectional study on 145 emerging adults was conducted. Twins present a normative development pattern more frequently and a warmer sibling relationship than non-twin siblings. A normative development pattern is related to sibling relationships but not to the level of life satisfaction. In particular, normativity in residential conditions is linked with warmer sibling relationships, while nonnormativity in economic conditions is linked to more rivalrous relationships. These data support the assumption that during emerging adulthood a normative development pattern is linked to a more positive sibling relationship.