Siblings serve an important role within each other's lives throughout the life course. The relationships between siblings do not develop in isolation; sibling relationships are governed by the rules and expectations of the family of origin. One of these characteristics is family distance regulation, which consists of two components: separateness and connectedness. The interplay between these two components may influence the quality of the sibling relationship as well as individual outcomes, such as stress and depression. This study utilized Actor Partner Interdependence Models to understand the associations between these variables within sixty four sibling pairs (thirty three female female dyads, thirty one female male dyads) during emerging adulthood, a transitional developmental period. Overall, it appears that family distance regulation is not associated with sibling relationship quality, save for within female male dyads. Brother's separateness was associated with lower sister's perceived warmth between siblings. Additionally, distinct patterns emerged between warmth and individual stress based on the gender make up of the dyad. Both sisters' warmth was associated with lower personal stress and higher sibling stress. This may indicate that during times of stress, sisters reach out to their other sister, signaling that the relationship is valued, thus increasing the warmth between the two siblings. This increase in warmth affirms that the individual has a support person in their sister, thus lowering their personal stress levels. Brothers' warmth was associated with higher sisters' stress and sisters' stress was associated with higher brothers' stress. This may indicate that if the sibling relationship is highly valued, i.e. has higher warmth, the transitions of emerging adulthood may constrain the relationship, which increases the stress experienced by the siblings. Finally, personal stress was associated with higher personal depression, furthering the importance of sibling relationships during this time period. These results indicate that the sibling relationship may be a crucial support figure during the transitional period of emerging adulthood. Future research should replicate these findings to further the field's understanding of sibling relationships and explore how the family of origin influences siblings. With continued research and investigation, interventions could be developed to foster sibling relationships to enhance their protective factors, especially during emerging adulthood.

Even in advanced economies where family sizes has declined over the last 50 years, most children and youth today have at least one sibling. Despite this ubiquity and the known mental health benefits from a supportive sibling relationship, research on emerging adulthood has rarely examined if siblings may contribute in reducing psychological distress. Hence, the overarching question of my thesis was to examine mechanisms (protective, compensatory, and promotive) through which sibling support may mitigate the risky effects of parent and peer alienation on stress and psychological distress in emerging adulthood. The literature in childhood and adolescence appears to suggest that siblings are protective and foster mental health. However, the beneficial effects of siblings have rarely been theorized at the beginning of adulthood, notably in college students who are known to develop more independence from their family. Nevertheless, I was able to ground my thesis in two well-established theoretical frameworks. First, the stress-buffering hypothesis, which postulates that perceived social support should counteract the adverse effects of stress on mental health. Second, concepts of developmental psychopathology, which operationalize the notions of risk, protective, promotive and compensatory factors. Four empirical studies, presented across three articles, were conducted to address the overarching question of this thesis. In Article 1, which presents the first study, we examined the protective role of a supportive sibling climate (i.e. supportive experiences across all siblings) in the hypothesized moderated-mediation model across three independent samples of emerging adults (N=310, N=259, and N=416) using latent moderated structural equation modeling (LMSEM). The hypothesized moderated-mediation model examined the protective (moderating) role of sibling support in a mediation model of the effect that parent and peer alienation has on psychological distress through stress. Inconsistent with our hypothesized model, sibling climate did not moderate the paths linking parent and peer alienation to stress and psychological distress. Nonetheless, in support of the risk mediation model, general stress partially mediated the link between parent (and not peer) alienation and psychological distress. This first study underscored that while not protective, a supportive sibling climate may be a promotive of mental health, and that parents may have an enduring influence during emerging adulthood given that experiences of alienation in these relationships was indicative of more stress and psychological distress. In Article 2, which reports the second and third studies, we used the same moderated-mediation model to examine whether a supportive sibling relationships with one's closest sibling could have protective effects among emerging adults (N=789 and N=325). Additionally, the mediating role of two stress-related mechanisms we also tested: (a) stress in general (Study 2) and interpersonal stress specific to parents and peers (Study 2 and 3). Contrary to our hypothesized protective effects, these studies found mixed effects in the form of both accentuating and attenuating influences of sibling support in the links among alienation, stress, and psychological distress. In Study 2, a worsening effect of siblings suggested peer alienation was related to more stress but only when emerging adults receive more support from a sibling. At the same time, stress from peer alienation was related to less psychological distress in the context of more sibling support. In study 3, a buffering effect of siblings indicated parent alienation was related to less psychological distress in the context of higher levels of support from siblings. Partly consistent with the proposed mediation model, both studies found parent and peer alienation were associated with more psychological distress and this path is mediated by stress in general and not interpersonal stress (only Study 2). Overall, these studies imply sibling support only partially and rarely buffers the link between experiences of alienation and psychological distress as these protective effects failed to replicate across the studies. Given the limited evidence for the protective role of siblings in the moderated-mediation model, in the last article, which reports the fourth study, we focused on the compensatory role of siblings on the development of stress and psychological distress over a semester, specifically in the context of parent and peer alienation among emerging adults (N =234). The 3-month longitudinal findings suggest psychological distress and stress decrease over the course of three academic months. Furthermore, parent and peer alienation nor sibling support were not predictive of stress or psychological distress over time. Taken together, we found supportive sibling relationships, whether across multiple siblings or with one sibling, may not have a protective or compensatory effect against stress and psychological distress when accounting for experiences of alienation from parents and peers in emerging adulthood. Thus, the benefits of siblings in emerging adulthood might at best be promotive in the context of alienation. Furthermore, parent and peer alienation were not identified as risk factors in the longitudinal study, while they were consistently associated with stress and psychological distress in the cross-sectional studies. Finally, unexpectedly, stress and psychological distress were found to decrease over a semester suggesting emerging adults might be more resilient to manage the challenges of a semester than often claimed. In conclusion, to answer the overarching question of this thesis, these findings suggest emerging adults might not be able to rely on their sibling relationships to protect them from psychological distress when faced with stressful experiences of parent and peer alienation. Rather, their supportive siblings might only mitigate psychological distress in the absence of any of these harmful experiences.

Sibling relationships are special in many ways, not least because often siblings are the family members who go through their whole lives together But those relationships can be fraught with strife or tension, bouts of happiness or strain and stress. They can predict and affect other relationships in our lives, and they can offer solace or sadness over the years. Here, Suzanne Degges-White looks at the variety of sibling relationships with an eye to improving both the good and the bad. Using real stories throughout, the author illustrates the broad spectrum of problems (and rewards) that can come from having a sibling. Examining such factors as the early family constellation, birth order, cultural diversity, and family communication patterns, Degges-White illustrates how these relationships can affect so many other areas of our lives, and considers how adult sibling conflict, rivalry, abuse, and loss influence our lives. She offers suggestions for effective responses to adult sibling conflict as well as enhancing family communication and deepening the sibling connection in adulthood. No matter what the sibling relationship is or has become, this work will help readers consider how situations might be improved or addressed, even if it means letting go of unhealthy sibling relationships.

This edited volume presents unique insights on sibling relationships in adulthood in the early 21st century, focusing on three themes: relations beyond childhood and school years; factors shaping social support provision between siblings; and changes in family life and how these impact sibling relations. Comprised of chapters from distinguished international family scholars, this book examines sibling dynamics across age, race, culture, gender, sexual orientation, geography, and social environments. It answers important questions such as, to what extent do siblings support each other at different stages of the life cycle? How do cultural practices and family obligations impact on sibling support? How does sibling support differ when looking at surrogates, migrant families, polygamous families, and siblings with disabilities? These contributions expand and contribute greatly to the field of sibling studies and will be of interest to all students and scholars studying and researching family relationships.

The bond siblings develop in childhood may be vastly different from the relationship that evolves in adulthood. Driven by affection but also characterized by ambivalence and ambiguity, adult sibling relationships can become hurtful, uncertain, competitive, or exhausting though the undercurrents of love and loyalty remain. An approach that recognizes the positive aspects of the changing sibling relationship, as well as those that need improvement, can restore healthy ties and rebuild family closeness. With in-depth case studies of more than 260 siblings over the age of forty and interviews with experts on mental health and family interaction, this book offers vital direction for traversing the emotional terrain of adult sibling relations. It pursues a richer understanding of ambivalence, a normal though little explored feeling among siblings, and how ambiguity about the past or present can lead to miscommunication and estrangement. For both professionals and general readers, this book clarifies the most confounding elements of sibling relationships and provides specific suggestions for realizing new, productive avenues of friendship in middle and later life—skills that are particularly important for siblings who must cooperate to care for aging parents or give immediate emotional or financial support to other siblings or family members.

This study examined whether the quality of the sibling relationship can alter the negative impact of stress on child well being. Participants were of 311 families (236 two parent families and 75 single parent families) with an adolescent child (M age of child at Time 1 = 11.25, SD = .99, 51% female) who took part in the Flourishing Families Project. Data were assessed using both a multiple time point cross-section and a two wave longitudinal design. Hierarchal linear regression suggested that when assessing the direct effects of sibling on well being, sibling affection is a better predictor of well being, but when assessing indirect effects, sibling conflict is a better predictor. Little evidence was found to support the idea that siblings moderate the impact of stress by buffering or decreasing the negative impact of stress. Results did indicate that sibling conflict was a salient moderator of stress in that conflict exacerbates the already negative impact of stress. Results from this study also suggest that when assessing the buffering or exacerbating impact of siblings, cross-sectional data produces better explanatory power than when these constructs are assessed longitudinally. However a single time point, cross-sectional design does not account for dynamic changes over time in either the sibling relationship, the level of stress or well being. Research designs such as multiple time, point cross-sectional studies or growth curve analyses are recommended.

When one begins to examine the existing literature dealing with siblings, one soon becomes aware that many separate domains of sibling research exist and that there is little connection between them; for example, sibling relationships in early childhood, genetic and environmental influences on individual differences between siblings, dysfunctional sibling relation ships, adult sibling helping relationships, sibling violence and abuse, and so on. The author's aim in writing this book was to attempt to bring together for the first time studies from diverse areas of sibling research into a single volume. The book is a summary and integration of the various domains of sibling studies, extending across the life span where studies exist to make this possible. Although many gaps in the sibling research literature within and between domains of study and over the life span still exist, it is hoped that this book will motivate others to help fill in the gaps by suggesting direc tions where further research is needed.