The family constellation, or structure of the family, the relationships within the family, and the characteristics of the individual children all impact sibling relationships. Family constellation refers to the number and sex of the adults and children including the birth order, type of relationship (biological, adopted, stepparent or sibling), age, and spacing of the children. Although all relationships in the family are important, the parent-child relationships have the greatest impact on sibling relationships. Individual differences among siblings also impact their relationships. When children are younger, temperament is important in sibling relationships but for older children, relationships are influenced by their personality and social and cognitive skills. Family life varies greatly and many factors influence the outcome for children.

Birth Order

The relationship between birth order and an individual's personality has been debated since Alfred Adler (1928) described specific characteristics of children according to their birth order. He also coined the phrase "sibling rivalry." Although a number of factors affect the outcomes for children, many authorities believe that children's birth order plays a special role in their destiny.

Firstborn Children

Firstborn children, who are often surrogates for their parents as caregivers, teachers, and models, enjoy a greater status/power position in relationship to their younger siblings. This difference becomes more pronounced as the age gap increases for at least up to four years. In children's eyes, status/power is conferred most heavily on the eldest son (Furman and Buhremester, 1985). Older girls are more often good teachers and nurturers for younger children (Cirirelli, 1972). Older boys, on the other hand, tend to be better stimulators and models (Cirirelli, 1972). The oldest sibling feels more rivalry over the birth of the second child than other birth orders do toward a new baby. This is because the firstborn has had the full attention of parents and now has to share their affections. The adverse effects of this dethronement can be modified if parents prepare the older child for the changes and give her or him special attention after the new baby arrives. In this case, the older sibling often becomes protective of the new family member (Adler, 1928; Teti, Sakin, Kucera, Corns, and Eiden, 1996).

Firstborn children tend to have distinct personality traits. Many studies depict these children as more adultlike, achievement-oriented, verbal, conservative, controlling of subordinates, and displaying a higher self-concept, but more anxious and less popular with peers than children born later (Lahey, Hammer, Crumrine, and Forehand, 1980; Zajonc, 1983). Success seems to fit firstborn children. Many firstborns show leadership qualities. Alfred Adler said firstborns were in a favorable position being larger and stronger, but, to keep their position, they also had to be more clever (1928). In studies as early as Galton's English Men of Science (1874), disproportionate numbers of firstborns have achieved eminence. A higher percentage of firstborn children have become scientists, professors, presidents, Rhodes scholars, and astronauts. More firstborns have been finalists in the National Merit Scholarship tests compared to any other birth order (Muzi, 2000). This advantage may be explained by the fact that firstborns have only adults for language models and social interactions in the most formative period while their siblings are influenced by their predecessors in the family.

Only Children

It is not surprising that only children have many of the characteristics of firstborns with siblings (Falbo and Polit, 1986). Their relationship tc their parents is similar and both are responsive to adults. Parents provide an adul~ intellectual environment for these children. In the case of the only child, this environment remains unchanged by the presence of younger children.

Although both groups surpass other birth orders in intellectual and academic achievements, only children, as a group, score higher than other firstborns. They also complete about three additional years of schooling, achieve higher occupational prestige, and earn more money than firstborn children with siblings (Blake, 1989; Falbo, 1984; Falbo and Polit, 1986). However, a study on birth order by Steelman and Powell (1985) shows no correlation between birth order and academic success.

Only children miss the experiences of sibling relationships and of having to share their parents with siblings. However, the stereotype of only children as more lonely, selfish, spoiled, and maladjusted than children with siblings is not true. A study of only children placed them into three groups. Some were normal and well adjusted, others were impulsive and acting out, and others were similar to the stereotype of only children (Rosenberg and Hyde, 1993).

Middle Children

Middle children are more sociable and harder to classify than the firstborns. They are sometimes called the "overlooked child." It is more difficult to be the middle child when all siblings are of the same gender. If second-born children are closer in age to the oldest, they tend to take on some of these characteristics. This is especially true when the second-born is the oldest girl in a large family. On the other hand, middle children tend to be less adaptive to parental values, perhaps because they want to avoid competition with the older child. Because firstborn children mirror their parents in searching for their identity, middle children turn to peers, often adopting some of their values. In contrast to the first-born the middle child may be more friendly, cheerful, placid, and less studious with lower self-esteem. According to Adler (1928), the middle child is ambitious, rebellious, envious, and better adjusted than either the first born or the youngest child.

Youngest Child

When growing up, the youngest child is smaller, weaker, less knowledgeable, and less competent compared to older siblings, and often turns to attention-seeking. At a very early age, the youngest are more outgoing, exploring toys, making responses to people, and initiating more play with strangers. Youngest children are significantly more successful socially than other birth orders (Steelman and Powell, 1985). The younger or youngest sibling is more dependent on others for help. Their dependency, however, deprives them of status/power and may lower their self-esteem.

Spacing, Gender, and Age

Most children are born within two or three years of the last sibling's birth (Dunn; 1995). Spacing of less than two years or five or more years is beneficial for the child's adjustment to a new sibling (Dunn, 1995; Teti, et al., 1996). A child under age two cannot realize all the implications of another sibling to their special position. In addition, young children closely spaced spend more time together than with their parents during these years and learn to understand each other intimately (Jaffe, 1997). After age two, resentment and rivalry increase until children reach age five or six. By this time their world outside the family has expanded and they are better able to cope with and/ or avoid some of these feelings (Dunn, 1995). All children, including the newborn, benefit from larger intervals between births. Parents have time to give them more individual attention.

Age differences, gender, and the ages of children in the family account for differences in the quality of their sibling relationships. Younger siblings admire most their siblings who are four or more years older. As already mentioned, the warmth-closeness characteristic appears greater between same-gender siblings and increases with the closeness of their ages. (Furman and Buhremester, 1985). On the other hand, conflict and competition are also more intense when siblings are close in age and, particularly, the same gender. Sibling rivalry is most intense in the early years and diminishes, at least on the conscious level, as siblings approach maturity.

Family Size

There are differences in growing up in a small family (one or two children) as opposed to a large family (over four children). The larger the family, the greater is the number of relationships for a child to experience, which can be enriching or frustrating or both. Discipline in large families is more rule oriented, less individualized and there is more corporal punishment (Wagner, Schubert, and Schubert, 1985). Children in small families have fewer experiences in relationships but do have more individual time with their parents. According to some studies, they also have slightly higher test scores, more schooling, and achieve more academically and in their occupation than children from large families (Blake, 1989; Hauser and Sewell, 1985).

Parent-Child Relationships

The quality of the relationship between each child and parent and between parents affects the sibling relationships. Parents who are constructively responsive to their children foster good feelings and cooperative behavior among their children (Furman, 1995; Bryant and Crockenberg, 1980). In homes where fathers are affectionate and helpful there are more positive sibling interactions. On the other hand, conflict between mother and each child is associated with increased sibling conflicts (Volling and Belsky, J. 1992). The child's temperament, sex, health, or hereditary traits also affect sibling relationships. Parents sometimes understand one child better than another. The child's temperament gender, health, or hereditary traits affect this relationship. When children perceive parental partiality, it increases feelings of competition, conflict, and jealousy among siblings. Most children believe that their parent has a favorite child, which may not be true (Zervas and Sherman, 1994).

Sibling rivalry is a normal emotion growing out of the need to share biological and affectional ties of the two most important people in a child's world, his or her parents. When a baby comes along, a child's world changes greatly. The child or children in the family need to know about this ahead of time and be given special attention. The new baby does take time and energy from the parents and the other child or children do not receive the same kind of attention from parents, relatives, and friends as before. The author at age three-and-one-half said to a relative fussing over her new baby sister, "Aunt Olive, you can go home now and you don't need to come back again!"

A child development student told the following story about herself as a baby.

Her five-year-old brother asked their mother to bring his new baby sister to kindergarten for "show and tell time." Holding her, he told the class what a good baby she was and how cute she was. He then proceeded to say to his classmates: ''I'm looking for a good home for her."

This dethronement may best be understood by the following illustration:

The husband said to his wife, "Darling, I love you so much that I am going to bring home another wife. You will have someone to love and have fun with. You can share your clothes and jewels and let her drive your sports car. I won't love you any less, I'll just open up my heart and love you both the same. "

Through expressions of sibling rivalry, children are reacting to the denial or felt denial of their needs for dependence and the affection of their parents. To punish children for these acts of jealousy tends to confirm their feelings of loss and resentment. When parents try to treat each child as an individual and avoid making sibling comparisons, they reduce sibling rivalry. These actions also support each child's self-image. Parents can also do much to foster good sibling relationships by their responses to sibling conflicts. In children's arguments, parents should listen to both children, but never take sides. Parents should support children and help them find an acceptable solution. It is helpful when adults model good conflict resolution skills around children. Even though parental intervention may have a more equitable outcome, children do not experience how to resolve conflicts for themselves. Of course, violence should be prevented.

The roles that parents consciously or unconsciously assign to each child affect the qualities of the sibling relationship. This includes the degrees of warmth-closeness, status/power, cooperation or conflict, and rivalry each sibling feels. Is the older sibling given frequent and considerable responsibilities in caring for the younger ones or just an occasional role? Is the younger child given certain responsibilities or helped to develop talents that are different from the older siblings? Do parents label one child the troublemaker, another child the responsible one, and yet another one the baby? Children will tend to fulfill the role assigned to them.

Parenting Tips to Reduce Sibling Rivalry

  1. Consistent, positive, and developmentally appropriate rules
  2. Nurture each child as a valued individual and spending individual time daily
  3. Avoid sibling comparisons
  4. Avoid taking sides in sibling conflicts but support them in resolving their disputes

Individual Children's Characteristics and Sibling Relationships

As in any relationship, individual characteristics shape the nature of the sibling relationship. Some research has shown that temperament and sociability can influence the qualities of the relationship (Kendrick and Dunn, 1983). Do two siblings enjoy doing things together? Are many or few of their interests the same? Are both outgoing, wanting to be with other people or adventurous, trying new things?

Would they rather spend a sizable amount of time alone reading or working on a hobby? Does one like to take the lead and the other one follows? Is one or are both children moody, unable to deal with frustration, or poor sharers? Sharing experiences, whether failures or successes, bring siblings closer together. Having fun or helping each other also strengthens sibling bonds. Later in life, reminiscences are important. All this affects the short- and long-term closeness, power/status, cooperation/conflict, and rivalry in each relationship.

Sibling Interaction on Development

Children's personalities, social and cognitive skills, self-concepts, values, and sense of protection from the outside world are influenced by their sibling relationships. Siblings also affect children's roles in peer groups, in selecting friends, and in the larger world. The interests and skills children develop in their sibling relationships are often repeated later in choosing an occupation, mate, or deciding on the number of children to have. Siblings influence all sorts of competencies. This is particularly true in their play, especially the dramatic play of children under age six. One example is the close similarity of siblings in tests of creative thinking.

Children's self-image and gender role is first formed in the family. How children interpret the way parents and siblings see them affects what they think about themselves. A sibling is like a looking glass in which a child's thoughts and values are reflected. "Is this behavior acceptable?" "Are my ideas good or bad?" Older siblings are gender models for behavior and attitudes. An older brother becomes particularly important to a young boy in a home where there is no father.

Siblings protect each other outside the family and provide an emotional anchorage to each other in times of stress or crisis. Although relationships change over the years and distance may limit contact, siblings find strength in each other in times of crisis or celebrations like funerals or weddings. For better or for worse, sibling relationships are for life!