Approximately 80 percent of American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 children have one or more siblings, including both sisters and brothers, and at a young age relationships between siblings tend to be very hostile. Between the ages of two and four, siblings on average have a conflict once every ten minutes, and from there tend to decrease between the ages of five and seven. When parents come across this conflict they tend to do one of three things:

1. Intervene and try to help them resolve the conflict
2. Admonish or threaten them
3. Ignore it

In families with siblings two to five years in age, parents tend to do nothing when conflict arises. Laurie Kramer, who has conducted studies involving siblings, says that not intervening and letting sibling conflict escalate won't solve it.

However, conflict is not the only case when it comes to siblings. Sibling relationships include helping, sharing, teaching, fighting, and playing. One study found that adolescent siblings spend on average about ten hours a week together and an average of twelve percent of that time doing constructive activities. Mexican-American siblings tend to spend more time together, averaging at about seventeen plus hours per week.

Judy Dunn (a leading expert on sibling relationship) in 2007 described three important characteristics of sibling relationships.
Emotional quality of the relationship: Both intensive positive and negative emotions are often expressed by siblings toward each other. Many children and adolescents have mixed feelings toward their siblings.
Familiarity and intimacy of the relationship: Siblings typically know each other very well, and this intimacy suggests that they can either provide support or tease and undermine each other, depending on the situation.
Variation in sibling relationships: Some siblings describe their relationships more positively than others. Thus, there is considerable variation in sibling relationships. We've indicated that many siblings have mixed feelings about each other, but some children and adolescents mainly describe their siblings in warm, affectionate ways, whereas others primarily talk about how irritating a mean a sibling is.

One recent study of 384 adolescent sibling pairs revealed that sixty-five percent of their mothers and seventy percent of their fathers showed favoritism toward one sibling. When favoritism of one sibling occurred, it was linked to lower self-esteem and sadness in the less-favored sibling. In many situations siblings understand each other's problems and dilemmas better than the parents can. These topics include: dealing with peers, coping with difficult teachers, discussing a tattoo and piercing, and sex.

Around the world

Parents in the United States of America tend to delegate responsibility for younger siblings to older siblings primarily to give the parents freedom to pursue other activities. However, in non-industrialized and in less developed countries, the older sibling's role as a caregiver to younger siblings has much more importance. In industrialized countries, the older sibling's caregiving role is often discretionary; while in non-industrialized countries, it is more obligatory.

Birth order

Firstborn children are more adult oriented, helpful, conforming, and self-controlled. They also excel in academic and professional endeavors. However, they tend to have more guilt, anxiety, and difficulty in coping with stressful situations. Some researchers claim that the birth order has a profound impact on a childs personality, however, this assertion has been repeatedly challenged. Firstborns do not have to share their parents attention with another sibling, until the second child arrives. When the second child is born, the firstborn tends to receive less attention on the account that a newborn requires so much individualized attention. In one research study, mothers became more negative, coercive, restraining, and played less with the firstborn following the birth of the second child. Only children in the family have a common perception of being spoiled. However, research has shown that only children in the family often are achievement orientated and display a desirable personality, especially in comparison with later-borns and children in large families. In China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 one-child families are becoming more and more popular because of the strong motivation to limit the population growth. There also other factors that can influence siblings relationship to another, such as heredity, models of competency or incompetency that parents present to children on a daily basis, peer influences, school influences, socioeconomic factors, sociohistorical factors, and cultural variations.

Sibling relationships in adulthood

Eighty-five percent of today's adults in America have at least one living sibling. Sibling relationships in adulthood may be extremely close, apathetic, or highly rivalrous. The majority of sibling relationships in adulthood have been found to be close. Those siblings who are psychologically close to each other in adulthood tended to be that way in childhood. It is rare for sibling closeness to develop for the first time in adulthood.

Sibling relationships depicted in pop culture and fiction

• In the cartoon Hey Arnold, the character Helga Pataki resents her older sister, Olga Pataki who is an overachiever (see perfectionism
  Perfectionism (psychology)
  Perfectionism, in psychology, is a belief that a state of completeness and flawlessness can and should be attained. In its pathological form, perfectionism is a belief that work or output that is anything less than perfect is unacceptable...
  
  ). Helga is neglected and ignored by their parents. However, when they do give her any attention, they compare her to Olga. In many episodes, the father absentmindedly calls Helga "Olga" much to her disdain. Olga receives all of the attention from their parents and in one episode she told Helga that she feels pressured by their parents to be perfect.