Sibling
[2][3] The word sibling was reintroduced in 1903 in an article in Biometrika, as a translation for the German Geschwister, having not been used since Middle English, specifically 1425.
[11] One notable example of three-quarter siblings is the family of American aviator Charles Lindbergh, who fathered children with two German sisters, Brigitte and Marietta Hesshaimer.
[24] Twin studies have been conducted by scientists to examine the roles that genetics and environment play in the development of various traits.
A person may share more than the standard consanguinity with their sibling if their parents are related (the coefficient of inbreeding is greater than zero).
Typically, researchers classify siblings as "eldest", "middle child", and "youngest" or simply distinguish between "first-born" and "later-born" children.
Despite its lasting presence in the public domain, studies have failed to consistently produce clear, valid, compelling findings; therefore, it has earned the title of a pseudo-psychology amongst the scientific psychological community.
[citation needed] In his book English Men of Science: Their Nature and Nurture (1874), Galton noted that prominent composers and scientists are over-represented as first-borns.
[32] He theorized three main reasons as to why first-borns are generally more eminent: Today, the flaws and inconsistencies in birth order research eliminate its validity.
It is very difficult to control solely for factors related to birth order, and therefore most studies produce ambiguous results.
(Blake, 1981) provide three potential reasons for the higher scoring of older siblings on IQ tests:[32] Robert Zajonc proposed that the intellectual environment within a family is ever-changing due to three factors, and therefore more permissive of first-born children's intellectual advancement:[32] In 1996, interest in the science behind birth order was re-sparked when Frank Sulloway’s book Born To Rebel was published.
In this book, Sulloway argues that firstborns are more conscientious, more socially dominant, less agreeable, and less open to new ideas compared to later-borns.
While being seemingly empirical and academic, as many studies are cited throughout the book, it is still often criticized as a biased and incomplete account of the whole picture of siblings and birth order.
[39] Literature reviews that have examined many studies and attempted to control for confounding variables tend to find minimal effects for birth order on personality.
[40][41] In her review of the scientific literature, Judith Rich Harris suggests that birth order effects may exist within the context of the family of origin, but that they are not enduring aspects of personality.
The American Academy of Pediatrics suggests that instead of protesting or telling children to act their age, parents should simply grant their requests without becoming upset.
The University of Michigan Health System advises that most occurrences of regressive behavior are mild and to be expected; however, it recommends parents to contact a pediatrician or child psychologist if the older child tries to hurt the baby, if regressive behavior does not improve within 2 or 3 months, or if the parents have other questions or concerns.
[45] Sigmund Freud saw the sibling relationship as an extension of the Oedipus complex, where brothers were in competition for their mother's attention and sisters for their father's.
In a study by Volling, four classes of children were identified based on their different responses of jealousy to new infant siblings and parent interactions.
Some research has suggested that children display less jealous reactions over father-newborn interactions because fathers tend to punish negative emotion and are less tolerant than mothers of clinginess and visible distress, although this is hard to generalize.
[49] Malleable Theorists display engaging behaviours, like interacting with the parent or sibling in an attempt to improve the situation.
[49] They tend to have more intense and longer-lasting feelings of jealousy because they spend more time ruminating on the situation and constructing ways to make it better.
[49] Fixed Theorists display non-engaging behaviours, for example retreating to their room because they believe none of their actions will affect or improve the situation.
[48] This is due to their ability to mentally process the social situation in a way that gives them more positive, empathetic feelings toward their younger sibling.
[48] Older children are also better at self-regulating their emotions and are less dependent on their caregivers for external regulation as opposed to their younger siblings.
These types of fights seem to be more important to older siblings due to their larger desire for independence.
In addition, sibling warmth is not a protective factor for the negative effects of anxiety, depression, lack of self-worth and lower levels of academic competence.
McHale and her colleague conducted a longitudinal study using middle-childhood aged children and observed the way in which the parents contributed to stereotypical attitudes in their kids.
[56] In contrast, in homes where the father did not hold traditional values, the house chores were divided more equally among his kids.
[56] Anthropologist Edvard Westermarck found that children who are brought up together as siblings are desensitized to sexual attraction to one another later in life.
It can be seen in biological and adoptive families, but also in other situations where children are brought up in close contact, such as the Israeli kibbutz system and the Chinese shim-pua marriage.
