You will respond to the following prompt for your discussion post on the textbook chapter about families.
Students in a classroom come from various family contexts (e.g. parenting styles, sibling relationships, socioeconomic background, etc.). How might this play out in an educational context? Be specific using examples from the textbook. What are some things schools can do to support students from different family contexts? Provide at least one suggestion.
SUSAN M. MCHALE The Pennsylvania State University
KIMBERLY A. UPDEGRAFF Arizona State University*
SHAWN D. WHITEMAN Purdue University**
Sibling Relationships and Influences in Childhood
and Adolescence
The authors review the literature on sibling relationships in childhood and adolescence, starting by tracing themes from foundational research and theory and then focusing on empirical research during the past 2 decades. This literature documents siblings’ centrality in family life, sources of variation in sibling relationship qualities, and the significance of siblings for child and adolescent development and adjustment. Sibling influences emerge not only in the context of siblings’ frequent and often emotionally intense interactions but also by virtue of siblings’ role in larger family system dynamics. Although siblings are building blocks of family structure and key players in family dynamics, their role has been relatively neglected by family scholars and by those who study close relationships. Incorporating study of siblings into family research provides novel insights into the operation of families as social and socializing systems.
Department of Human Development and Family Studies, 601 Oswald, The Pennsylvania State University, University Park, PA 16801 ([email protected]).
*School of Social and Family Dynamics, 951 S. Cady Mall, Arizona State University, Tempe, AZ 85287.
**Department of Human Development and Family Studies, Hanley Hall, Purdue University, West Lafayette, IN 47907.
Key Words: adolescents, childhood/children, family process, sibling relations.
Siblings are a fixture in the family lives of children and adolescents, and a body of work documents their role in one another’s everyday experiences as companions, confidantes, com- batants, and as the focus of social comparisons. Research on sibling relationships has been aimed at identifying factors that explain these and other social dynamics between siblings and at exam- ining the role of sibling experiences in youth development and well-being. From this work we know that sibling relationships are shaped by factors ranging from child characteristics to cultural norms and values. We also know that siblings can have direct effects on one another’s development when they serve as social part- ners, role models, and foils and that siblings can influence one another indirectly by virtue of their impact on larger family dynamics—such as by serving as building blocks of the fam- ily structure, holding a favored family niche, or diluting family resources (McHale, Kim, & Whiteman, 2006).
Recent national data document the ubiquity of siblings in U.S. families, even in the face of declines in family size. Data from the Integrated Public Use Microdata Series’ harmonization of the 2010 Current Population Survey (King et al., 2010) indicate that 82.22% of youth age 18 and under lived with at least one sibling—a higher percentage than were living in a household with a father figure (78.19%). In 2010, the number of siblings in the household for youth age 18 and
Journal of Marriage and Family 74 (October 2012): 913 – 930 913 DOI:10.1111/j.1741-3737.2012.01011.x
914 Journal of Marriage and Family
under averaged 1.51, with almost 40% of youth living with one sibling, about 25% living with two siblings, and over 15% living with 3 or more siblings. Given changing U.S. demographics, it is important to note that these data also revealed variability in sibship size across racial/ethnic groups, with Asian (M = 1.41) and White (M = 1.49) youth having fewer siblings and African American (M = 1.64) and Hispanic youth (M = 1.68) growing up with more siblings. Divorce, remarriage, and multipartner fertility patterns also have had implications: In 2010, more than 10% of households with children included step- or adoptive siblings.
In the face of their ubiquity and potential for influence, however, sibling relationships have been relatively neglected by researchers study- ing close relationships and by family scholars, in particular. Our search of the 1990 – 2011 psycho- logical and sociological abstracts for ‘‘sibling and relation or relationships,’’ for example, yielded 741 citations. In contrast, the counts were 33,990 citations for ‘‘parent or parenting,’’ 8,685 citations for ‘‘marriage or marital relation- ship or marital relation,’’ and 5,059 citations for ‘‘peer relations or peer relationships or friend- ships.’’ Drilling down to the abstracts of the major family journals between 1990 and 2011 and focusing on the neonatal through adolescent periods yielded citation counts of 41 articles in the Journal of Marriage and Family, 18 articles in Family Relations, 21 articles in the Journal of Family Issues and 131 articles in the Jour- nal of Family Psychology with the term sibling in the abstract; only about one third of these articles, however, focused directly on sibling relationships.
Given their relative neglect, the overarching goal of this article is to stimulate interest of family scholars in sibling relationships by portraying the centrality of siblings in family life and sibling influences on child and adolescent development. In so doing we also aim to illuminate the ways in which the study of sibling relationships and dynamics can inform our understanding of how families operate as social and socializing systems. Our review is divided into four sections. First, to introduce family scholars who are new to the field to research on siblings, we begin with an overview of the theoretical traditions and early studies that provide the foundation for contemporary research. This early work was aimed primarily at two topics: (a) factors that shape sibling
relationship qualities and (b) sibling influences on one another’s development. In the second and third sections of this article, we review research conducted between 1990 and 201l on these two topics. In the fourth and final section, we take stock of what we have learned to date about this primary family relationship and make recommendations for future research directions.
FOUNDATIONS OF RESEARCH ON SIBLING RELATIONSHIPS AND INFLUENCES
From its inception, research on siblings has been grounded in a range of disciplinary perspectives. Below we consider five traditions that continue to shape the field. We note, however, that a challenge for sibling relationship researchers is to better integrate concepts and methods toward an interdisciplinary approach to studying sibling relationships.
Sociological and Social Psychological Approaches
One early line of research focused on the significance of sibling structure variables. From this perspective, siblings’ position in the family gives rise to social psychological processes, with lifelong implications for individual development and adjustment (Irish, 1964). Interest in birth order and its impact on achievement emerged in the late 1800s, with Galton’s (1874) analysis of British scientists. Galton concluded that the overrepresentation of firstborns in science leadership was due to the rights and responsibilities conferred on them by laws and mores around primogeniture. As we describe later in this article, scholars from other traditions, such as Adler’s ethological/analytic perspective, also highlighted birth order effects but targeted social and psychological processes, such as firstborns’ dethronement and parents’ tendency to overindulge younger siblings, to explain birth order differences in siblings’ personality and psychological adjustment (Ansbacher & Ansbacher, 1956).
Beginning in the 1950s, sibling gender constellation became a focus (Brim, 1958; Koch, 1960). Findings from a study of 350 five- and six-year-olds, published in a series of monographs and articles, anticipated tenets of social learning theory in demonstrating that higher status, older siblings tended to be more influential models and that model similarity
Sibling Relationships 915
(i.e., same-gender siblings) enhanced a model’s impact. An important insight from this work was that sibling gender constellation effects emerged not only via parent-driven dynamics such as gendered differential treatment but also from siblings’ direct experiences with one another.
A third structure factor was sibship size, in particular its role in achievement. One early perspective that remains influential held that siblings dilute resources available to individual children and thereby limit their achievement (Blake, 1981), and population studies (Blau & Duncan, 1965) found evidence of sibship size effects on education and occupation attainment. A second, confluence model (Zajonc & Markus, 1975) held that families’ overall intellectual climate is a function of its age distribution as determined by number of children, age spacing between them, and children’s corresponding opportunities to teach and be taught by siblings.
A limitation of work on structural variables that persists today, however, is that the social and psychological processes purported to account for sibling constellation effects—such as rivalry, differential treatment, or resource allocation—were inferred on the basis of patterns of sibling outcomes instead of being measured directly. In a series of articles, Furman and Buhrmester (e.g., Buhrmester & Furman, 1990) examined links between structure characteristics and relationship dynamics. Their work showed that structure variables do not fully account for relationship processes and underscored that influence processes should be directly measured.
Psychoanalytic and Ethological Groundings of a Developmental Perspective
A second thread in contemporary research on siblings originated within the psychoanalytic and ethological traditions in the first half of the 20th century. Adler’s theory of individual psychology placed sibling dynamics at the center of family life and personality development (Ansbacher & Ansbacher, 1956). Adler argued that social comparisons and power dynamics in families, in particular sibling rivalry for family resources, were fundamental influences on personality development. He suggested that, as a means of reducing competition, siblings differentiate or de-identify, developing different qualities and choosing different niches. A handful of early studies found evidence consistent with
Adler’s ideas (Grotevant, 1978; Schachter, Shore, Feldman-Rotman, Marquis, & Campbell, 1976) and, as we later discuss, recent research on parents’ differential treatment of siblings also provides support for Adler’s hypotheses about the significance of sibling dynamics in psychological adjustment.
More generally, two themes from psychoana- lytic and ethological perspectives that influenced early sibling research were (a) the significance of early experience and (b) the adaptive functions of social behavior. The ethological tradition also was influential in its emphasis on naturalistic observation methods, an approach adopted by developmental scholars who examined the role of siblings in early socioemotional development (Abramovitch, Corter, & Lando, 1979; Bryant & Crockenberg, 1980; Dunn & Kendrick, 1980). On the basis of this early work, Dunn (1983) concluded that sibling relationships are unique in that they encompass both the complementary interactions typical of adult – child relationships and the reciprocal and mutually influential inter- actions of peers. Further, the frequent and often emotionally charged social exchanges of siblings serve as an impetus for socioemotional develop- ment as young children work to establish their status in the sibling relationship and their niche in the family. Finally, Dunn emphasized moving beyond structural variables to focus on influence processes and stressed the significance of study- ing sibling relationships within the larger family system. Thirty years after Dunn’s article was published, her ideas remain integral to research on sibling relationships and influences.
Learning and Social Learning Perspectives
Learning theories, targeting reinforcement and observational learning, were a third early influ- ence, and they continue to shape the literature on sibling influences. Early findings were consistent with the idea that siblings serve as role models (Brim, 1958). Also consistent were findings from observational studies documenting asymmetri- cal sibling influences, with toddlers imitating their (higher status) older siblings more than the reverse (Abramovitch et al., 1979).
Patterson (1984) broke new ground in his observational research on the sibling relationships of children with conduct disorders. Through analyses of observed reinforcement dynamics, Patterson concluded that sibling relationships can serve as a training ground for
916 Journal of Marriage and Family
aggression when siblings become involved in coercive cycles wherein escalation of negative behavior is rewarded by one partner giving in to the other’s demands. A key contribution of this work was that sibling influence processes were directly observed and measured, and Patterson’s insights continue to motivate contemporary research on siblings’ influences on risky behavior.
Contributions From Behavior Genetics
Studies in this tradition generally treat data on siblings as a methodological tool, comparing siblings of differing degrees of biological relat- edness to draw inferences about the relative roles of genes and environment in development. Such findings are not relevant to understanding sibling relationships, but behavior geneticists’ insights into the significance of the nonshared environment pointed to the potential significance of sibling influences in such forms as siblings’ position in the family structure, parents’ differ- ential treatment of siblings, and asymmetrical sibling interactions (Rowe & Plomin, 1981). Although the nonshared environment is not directly measured in most behavioral genetics research, Plomin and Daniels’s (1987) seminal article ‘‘Why are children in the same family so different from one another?’’ motivated new attention to these differentiation processes by sibling researchers.
Cross-Cultural Perspectives
Using ethnographic methods, cultural anthro- pologists have long highlighted the ubiquity of siblings in the lives of children and fami- lies (Whiting & Whiting, 1975). Research in this tradition aims to identify cross-cultural universals in social patterns and uncover the ecological bases of cultural differences. Sum- marizing results from work beginning in the 1950s, Weisner (1989) noted four cultural uni- versals in sibling relationships: (a) Structural characteristics provide a metric for comparison, and although cultures differ in the emphasis they place on them, these characteristics have implications ranging from their effects on fam- ily dynamics to their effects on cultural beliefs; (b) siblings are common companions growing up and share a family history; (c) in child- hood, siblings are ubiquitous across all primate species; and (d) cultures imbue sibling roles and
relationships with meaning because ‘‘siblings always matter’’ (p. 14).
Cross-cultural research emphasized the care- giving responsibilities of older siblings and the hierarchical structure of sibling roles in non-Western societies as well as cultural dif- ferences in dynamics such as rivalry and compe- tition (Nuckolls, 1993; Weisner, 1989). Weisner pointed to subsistence demands in the devel- opment of sibling dynamics, including sibling residence and inheritance patterns. In daily life, social institutions structure siblings’ roles and relationships, which in turn shape and reinforce cultural beliefs about siblings. Weisner also contrasted kin-focused societies, wherein sib- ling relationships serve as the ‘‘moral ideals,’’ with North American families, whose social institutions fail to promote sibling bonds and responsibilities after adolescence. Nonetheless, even in the Western world, elements of the moral ideal of sisterhood (‘‘Sisterhood is powerful’’) and brotherhood (‘‘He’s not heavy; he’s my brother’’) persist.
Weisner (1989) argued that cross-cultural analyses of sibling relationships provide insights into what is universal in human experience and into ecological factors that promote differences in sibling bonds across place and time. This tradition provides a foundation for emerging research on siblings from racial/ethnic minority groups within the United States that is beginning to examine cultural values and practices that explain variability in sibling dynamics and influences.
SOURCES OF VARIATION IN SIBLING RELATIONSHIPS
We turn now to research on factors that shape sibling relationship dynamics, ranging from characteristics of siblings themselves to the family and cultural contexts within which they are embedded. We also consider recent intervention research aimed at designing and evaluating programs that promote positive sibling relationships. As will be evident, much of this work is built on the theoretical perspectives we have just reviewed.
Role of Child Characteristics in Sibling Relationships
Early research on structural factors inferred social processes from status characteristics such
Sibling Relationships 917
as gender constellation and age spacing, and an important advance is research that goes beyond status characteristics to directly mea- sure siblings’ personal qualities in an effort to understand their impact on sibling ties. One line of work examined siblings’ temperament (Stoneman & Brody, 1993) showing that dif- ficult temperaments, in particular, were linked to sibling relationship difficulties. Later stud- ies tested temperament as a moderator of links between family conditions and sibling relation- ships, suggesting that siblings’ characteristics could exacerbate the effects of stressful family circumstances on sibling ties (Stoneman, Brody, Churchill & Winn, 1999). The latter work also highlighted the role of contextual characteris- tics in sibling relationships, a topic to which we return later.
Child effects also were evident in research on families with children who had a disability or a chronic illness. Research comparing sibling relationships and child adjustment in families with versus without a child with a disability or chronic illness revealed two patterns. First, dyads with a disabled or ill sibling consistently displayed more warmth and positive affect than typical-only dyads (Stoneman, 2001). Second, typical siblings of disabled or ill children had a slightly elevated risk of adjustment problems (Sharpe & Rossiter, 2002). This research tended to be grounded in a deficit model that assumed siblings of atypical youth were at risk (Levy- Wasser & Katz, 2004). Few studies included indices of positive adjustment, but the ones that did showed that there also can be benefits of growing up with a sibling with a disability or illness (Mandelco, Olsen, Dyches, & Marshall, 2003; McHale & Harris, 1992). This work implies that an atypical sibling may make for greater variability in children’s adjustment and that the conditions under which children adjust in more positive or negative ways are an important target for research.
Such insights come from research designs that move beyond group comparisons of adjustment outcomes to examine the processes—such as coping styles or family supports—that explain within-group variability among children with atypical siblings (McHale & Harris, 1992). Longitudinal research also is needed. Knott, Lewis, and Williams (2007) provided a rare picture of the development of sibling relationships of children with autism and Down syndrome. Such studies can illuminate how these
relationships evolve as the typical sibling takes on a more parentlike role, an important issue given parents’ concerns about who will care for the child with a disability when they themselves no longer can (McHale & Harris).
Family Influences on Sibling Relationships
Studying how sibling relationships are embed- ded within families advances our understand- ing of both sibling relationships and families as social systems. Although not traditionally applied to study of sibling relationships, a family systems perspective directs attention to the inter- dependence among the subsystems that comprise families (Minuchin, 1985) and provides an over- arching framework for examining how marital and parental subsystems are linked to sibling relationships. With respect to the marital sub- system, a meta-analysis that included eight studies on marital – sibling relationship associ- ations revealed that sibling relationships were more positive in divorced as compared with always-married families (Kunz, 2001). Other research showed, however, that sibling con- flict and negativity were higher in divorced and separated versus married families (Noller, Con- way, & Blakeley-Smith, 2008), and higher in single-parent versus stepparent and married fam- ilies (Deater-Deckard, Dunn, & Lussier, 2002). Inconsistent findings may be due to the dimen- sions of sibling relationships examined. Noller et al. classified siblings on the basis of the combi- nation of positivity and negativity and found that ‘‘affect intense’’ sibling relationships, character- ized by both high positivity and high negativity, were overrepresented in divorced and separated families as compared with married families. An important insight here is that understanding sib- ling dynamics requires simultaneous attention to multiple dimensions of the relationship.
Accumulating research also suggests that marital and family processes, such as spousal conflict, coparenting, and parenting behaviors, are better predictors of sibling relationship qual- ities than is family status (O’Connor, Hether- ington, & Reiss, 1998). Findings have generally been consistent with a spillover process, such that hostility and conflict in the marital subsys- tem and negativity in parent – child relationships are linked to sibling conflict (Kim, McHale, Osgood, & Crouter, 2006) and violence (Hoff- man, Kiecolt, & Edwards, 2005). Negativity in the parent – child relationship also was shown
918 Journal of Marriage and Family
to mediate links between marital and sibling subsystem dynamics (Stocker & Youngblade, 1999). Some youth may compensate for fam- ily negativity (e.g., in their parents’ marriage), however, by forming close sibling relationships, which in turn protect youth from adjustment problems (Jenkins, 1992; Kim et al.; Milevsky & Levitt, 2005). An important step is to iden- tify the conditions under which spillover versus compensatory processes emerge.
Family systems influences on sibling rela- tionships also have been studied via mothers’ and fathers’ differential treatment of siblings. Systemic family influences are evident in inves- tigations of mother – father patterns of differen- tial treatment and their implications for siblings (Kan, McHale, & Crouter, 2008; Solmeyer, Kil- loren, McHale, & Updegraff, 2011; Volling & Elins, 1998). This work suggests that incongru- ence between mothers’ and fathers’ differential treatment, such that one parent shows preferen- tial treatment toward one sibling and the other does not, may mark a parent – child coalition or breakdown in coparenting that is associ- ated with negative sibling and marital dynamics and poorer adjustment in both siblings. This work also exemplifies how including siblings in research on families allows researchers to cap- ture novel dynamics and illuminate how families operate as systems.
Sociocultural Factors in Sibling Relationships
Substantial variability in the cultural and fam- ily settings in which children’s and adolescents’ lives are embedded underscores the need to represent these diverse contexts in efforts to understand variations in sibling relationships. The rapid growth of ethnic minority and immi- grant populations (U.S. Census Bureau, 2011), underscores the need for greater attention to sibling dynamics in these groups. The litera- ture provides a foundation for understanding sibling dynamics among at-risk ethnic minority youth, but research on normative processes in ethnic minority youths’ sibling relationships and sources of within-culture variation is rare.
Studies of families in challenging circum- stances highlight the unique contributions of siblings to ethnic minority youths’ adjustment. For example, longitudinal data showed that the risk of teenage pregnancy increased fourfold for the younger sisters of Latina and African American adolescent mothers and that having
an older sister who became a parent before age 20 posed a substantially greater risk than having a mother who became pregnant during adoles- cence (East, Reyes, & Horn, 2007). Among poor, rural, African American families, older siblings’ problem behaviors and attitudes were signifi- cantly linked to their younger siblings’ conduct problems (Brody, Ge, et al., 2003).
Much less is known about the ways siblings contribute to one another’s positive development in ethnic minority families. One exception is a longitudinal study conducted by Brody, Kim, Murry, and Brown (2003), which showed that, in rural, African American, single-parent families, older siblings’ social and cognitive competence explained changes in younger siblings’ competencies via their self-regulation. How siblings promote positive development among ethnic minority youth in both high- and low-risk settings is an important direction for future research.
Other studies complement cross-cultural work (Nuckolls, 1993), using ethnic-homoge- neous research designs to illuminate sources of within-group variability in sibling processes. An advantage of ethnic-homogeneous designs is that researchers can target cultural practices and values specific to a cultural group. For example, familism and simpatı́a values in Mexican American families (Gamble & Modry- Mandell, 2008; Killoren, Thayer, & Updegraff, 2008; Updegraff, McHale, Whiteman, Thayer, & Delgado, 2005) and spirituality and ethnic identity in African American families (McHale, Whiteman, Kim, & Crouter, 2007) were linked to more positive sibling relationships. In contrast to ethnic-comparative designs, in which inferences about the role of culture are made on the basis of patterns of group differences, ethnic- homogeneous designs allow for direct tests of the role of cultural processes in sibling dynamics.
Sibling Relationship-Focused Interventions
Sibling relationships can be shaped deliber- ately in intervention programs designed to pro- mote positive and reduce negative dynamics. Although siblings have been largely overlooked in family-based prevention and intervention programs, targeting sibling relationships can provide a less stigmatizing entrée into fami- lies than focusing on parent – child or marital relationship problems (Feinberg, Solmeyer, & McHale, 2012). Defining the role of siblings in
Sibling Relationships 919
interventions broadly, current work falls into three areas: (a) interventions that target sib- lings of at-risk youth; (b) family-based programs whose effects cross over to benefit the siblings of targeted youth; and (c) programs designed to alter sibling relationships via changes in parents’ or siblings’ behaviors, skills, and cognitions.
In recognition of the potential family system effects of children’s disabilities and illnesses, some programs have been designed to support their siblings. One community-based program targeting children with chronic health problems and disabilities resulted in increases in siblings’ self-esteem, perceived support, and knowledge of siblings’ illness/disability and in declines in behavior problems (Williams et al., 2003). Equally important are prevention programs for siblings of youth with adjustment problems who are at disproportionate risk for exhibiting similar problems. East, Kiernan, and Chavez (2003) showed that younger sisters of adolescent mothers who participated in a multifaceted prevention program exhibited lower pregnancy and truancy rates compared with girls in the control group.
Effects of family-based programs can also cross over to nontarget siblings. An inter- vention for younger siblings of adjudicated youth found positive effects on nontarget ado- lescent, but not preadolescent, siblings: Ado- lescent siblings in the intervention group, as compared with the control group, showed declines in delinquency and deviant behav- iors (Brotman et al., 2005). These sibling effects were unexpected but suggest that family-based interventions aimed at reduc- ing problem behavior for multiple children in a family may be cost efficient and effective.
Only a few programs directly target sibling relationships, and these generally focus on reducing conflict and aggression (Kramer, 2004). Typically, parents are trained to address young children’s sibling relationship problems. In one study, mothers were taught to serve as mediators of sibling disputes, and the results revealed improvements in children’s conflict resolution, social understanding, and engagement (Siddiqui & Ross, 2004).
Kennedy and Kramer (2008) designed an intervention to promote prosocial sibling rela- tionship skills and reduce problem behaviors. A trial with European American siblings in early and middle childhood demonstrated positive
effects, including enhanced emotional regula- tion and positive sibling relationship ratings postintervention. Feinberg and colleagues’ (e.g., Solmeyer et al., 2010) intervention for mid- dle childhood siblings was aimed at promot- ing social competencies and reducing sibling conflict via an after-school program with inter- spersed family meetings. Preliminary results provided evidence of the program’s effective- ness in improving