Siblings usually differ from each other in terms of their personalities and talents almost as much as unrelated children do. It is unlikely that two siblings will encounter the same set of parents. A times parents may feel that they need to encourage one of their children to be more social, while at the same time feel they need to constantly discipline another. This is most likely due to their differences in personality, and it is often the case where parents look at their children and ask themselves, why are they so different? Some of these differences may be due to temperament and genetics, but to a large extent, the disparity arises because children who grow up under the same roof actually experience very different families. One’s birth order in relation to their brothers and sisters is a key factor in the quality of the relationship between siblings. Although there are many factors that can affect sibling relationships, differences in age, gender, and family environment usually have a profound effect on the sibling relationship. Being the eldest of two, I believe that birth order greatly influences ones personality and relationship with their siblings.

Of the many factors that may affect the relationship between siblings, their ages, or space between each child in years is one of the biggest. Age spacing may also determine common experiences and interests giving them something to share. When there is a significant difference in age issues over power tend to rise. Each child tries to be the dominant one in the family so as expected there is a significant amount of conflict.
Sibling rivalry can be healthy for the relationship, and is often unintentionally encouraged by parents. I would hope that parents would become aware of the rivalry and interfere before it escalated as far as the image to the left depicts. First-borns tend to show more authority when dealing with younger siblings. Anything the first born does is a big deal, simply because it's a first for the family. First-borns usually have the luxury of being showered with undivided attention for a couple of years before a second child comes along. As a result, many first-born children end up with a lot of natural confidence. According to a
study, first-born children often have higher IQ’s than their siblings, are natural leaders and eager to please. The oldest tends to outshine their siblings academically, leaving the other children to feel inadequate; however the first-born may feel undervalued by parents if they sense that their parents have a close relationship with another sibling. Likewise, younger children feel bitter simply because the oldest child has the advantages of being older. This, however, forms a distinctive bond between them because the oldest feels they need to look after and teach the youngest, while the youngest needs to reach the standards set by the oldest. The study also suggest that in the event the first born were to die, another child were to be treated as the eldest, in that case there were no significant difference in IQ scores. This is because the the other child could benefit from advantages and responsibilities that are placed on the eldest.
Author
Kevin Leman, a psychologist and a leading expert on birth order, believes that for parents disciplining their children is much easier when birth order is taken into account. Leman, a father of five and author of The Birth Order Book: Why You Are the Way You Are, says that while every child is unique, birth order determines much of a child’s personality. In his book, Leman states that the oldest sibling tends to be serious, goal-oriented, conscientious, well organized, believers in authority, reliable perfectionists and self-reliant. Leman’s research implies that the middle child does not have a definite list of general characteristics like the oldest and youngest. The personality traits of a middle child are more contradictory. Leman found that middle children are mediators, picky about who they confide in, and tend to have fewer problems than the first-borns. Since the younger siblings are often inexperienced in certain situations, the younger sibling may look to their older sibling for help. This suggests that the middle child is able to experience both the role as an older sibling and a younger sibling. The experiences among siblings lay the foundation for their relationships with other siblings, peers, and determine their personality with respect to the role they play.
Other than age differences, gender and the family environment play a vital role in sibling relationships. The differences in gender greatly affect the roles that are assumed in the family and also affect the relationship with siblings. Same sex sibling pairs tend to be more pro-social and care giving towards each other. They have a higher percentage of constructive interactions and a lower percentage of negative interactions than different sex pairs. However, different sex pairs are better able to stay away from some of the competition that may occur between same sex siblings. This is largely due to children being treated differently by parents and receiving different kinds of attention based on their sex. Likewise, the family environment also influences the quality of sibling relationships. Parents play a vital role in determining the type of relationship their children will have with each other. How parents talk to the

first-born about the arrival of another child directly determines how the first-born will view their new sibling. While a new sibling can be viewed as a playmate, the child may feel left out and form resentment towards the sibling.
It is evident that the birth order theory is not without its flaws. An article in
Time magazine, as shown on the right, explored the power of birth order, and pointed out some holes in the theory. The effects of birth order are usually always based on a typical or normal family; therefore, dysfunction can throw it out of balance. In a 2005
study, investigators at the
University of Birmingham in Britain examined the case histories of 400 abused children and the 795 siblings of the abused children. Overall, they found that when only one child in the family was abused, the eldest child tended to be the scapegoat. When a younger child was abused, some or all of the other children were usually abused as well. Mistreatment of any of the children usually breaks the bond the parents have with the firstborn, turning that child from parental ally to protector of his siblings. At the same time, the eldest child may pick up some agreeableness skills from the younger children, which may aid in dealing with irrational parents. On the other hand the youngest child learns some of the firstborn's self-sufficiency.
This debate will never be entirely settled, and although for centuries parents have looked to birth order to determine what sort of people their children will become it is unclear if this theory has scientific merit. If anything, parents should look to themselves, and evaluate how they treat their own children. It is nearly impossible to treat ones children exactly the same, and small responsibilities, or lack of, that are placd on children actually help shape their personalities. There is no right way to raise a child, and it is important to expect differences, and embrace them. Yes, the theory of birth order and its effects on sibling relationships is not perfect; it brings us one step closer to explaining and understanding our own behavior.