A male sibling is called a brother; and a female sibling is called a sister. In most societies throughout the world, siblings usually grow up together development of strong emotional bonds such as love, hostility or thoughtfulness. The emotional bond between siblings is often complicated and is influenced by factors such as parental treatment, birth order, personality, and personal experiences outside the family.^[1]

Etymology [link]

Two siblings

Sibling is a modern revival of the Old English word sibling, meaning "relative, kinsman", a derivative of sibb "kinship, relationship", from Proto-Germanic *sibjō "race", from Proto-Indo-European *sebh-, *s(w)ebh- "tribe, one's own people". The term, along with its shortened form sib, may have been in use dialectally throughout the Middle English and Early Modern English periods, but was officially recognized c. 1903 when it came into common use in anthropology as a translation of the German genetics term Geschwister ("a brother or sister"). The word is further related to the second part of the word gossip, which derives from Old English gōdsibb, meaning "a sponsor, close relation".

Types of siblings [link]

Full sibling [link]

A "full sibling" (full brother or full sister) is a sibling with whom an individual shares the same biological parents.

Half-sibling [link]

Half-siblings only share one parent instead of two as full siblings do. Half-siblings can have a wide variety of interpersonal relationships, from a bond as close as any full siblings, to total strangers.

There are specific terms for referring to half-siblings based on the sex of the shared parent:

• Those that share the same mother (but different fathers) are known as a uterine sibling, or a maternal half-brother/sister.
• Those that share the same father (but different mothers) are known as an agnate sibling, or a paternal half-brother/sister. In law, the term consanguine is used in place of agnate.

In law (and especially inheritance law) half-siblings were often accorded unequal treatment. Old English common law at one time incorporated inequalities into the laws of intestate succession, with half-siblings taking only half as much property of their intestate siblings' estates as other siblings of full-blood. Unequal treatment of this type has been wholly abolished in England and throughout the United States.

3/4 sibling [link]

"3/4 siblings" are half siblings who share one parent and whose non-shared parents are full siblings. A similar situation arises when a man or a woman has children with two half siblings. 3/4 siblings share more DNA than half siblings, but less than full siblings. For example, if a man has a child with a woman and then fathers a child with her sister, the children will be 3/4 siblings. This term is more commonly used in animal breeding. A possible example was the relationship between Queen Elizabeth I of England, the daughter of Henry VIII and Anne Boleyn, and Henry Carey and Catherine Carey, the children of Mary Boleyn. Before her sister married King Henry, Mary was Henry's mistress, and he is sometimes named the father of her children. If so, Henry and Catherine would be 3/4 siblings of Elizabeth. 3/4 siblings are also in fact cousins at the same time. A present day example are Charles Lindbergh's children with his mistress Brigitte Hesshaimer, and his children with her sister, Marietta Hesshaimer. These children are collectively half siblings with his children with his wife, Anne Morrow Lindbergh.

Stepsibling [link]

A "stepsibling" (stepbrother or stepsister) is the child of one's stepparent from a previous or subsequent relationship. Not blood related.

Milk sibling [link]

Milk brothers or sisters are children breastfed by a woman other than their biological mother, a practice known as wetnursing and once widespread in the developed world, as it still is in parts of the developing world.

In Islam those who are fed in this way become siblings to the biological children of their wetnurse, provided that they are less than 2 years old. Islamic law (shariah) codifies the relationship between these people, and certain specified relatives, as rada'a; given that a child is breastfed five fulfilling (satisfactory to him) times, once they are adult, they are mahram, meaning that they are not allowed to marry each other, and the rules of modesty known as purdah are relaxed, as with other family members. But, laws of inheritance do not apply in the case of milk siblings.

Foster siblings [link]

"Foster siblings" are children who are raised in the same foster home, or are also foster children of the person's parents, or foster parents' biological children.

Adoptive siblings [link]

"Adoptive siblings" are when two children are legally related, but are not related by blood. Adopted siblings are not biologically related but may consider each other siblings because they act like they are.

• Adoptive siblings that are adopted by the same legal mother and father are considered full adoptive siblings.
• Adoptive siblings that are adopted by only the same legal mother are maternal adoptive half siblings.
• Adoptive siblings that are adopted by only the same legal father are paternal adoptive half siblings.

Cross siblings [link]

"Cross siblings" are not related in any way. Their only connection is that they share one or multiple half-siblings. For example, Michael is the maternal half sibling of Kevin, and the paternal half sibling of Eden. In this case, Kevin and Eden are cross siblings - they share no blood. Not to be confused with step siblings.

Sibling cousins [link]

"Sibling cousins" are those who have the same mother with their fathers being brothers or cousins or who share the same father with their mothers being sisters or cousins. This is a broader category than, but inclusive of, the 3/4 sibling above.

Birth order [link]

The Benzon Daughters by Peder Severin Krøyer.

Birth order is a person's rank by age among his or her siblings. Typically, researchers classify siblings as "eldest", "middle child", and "youngest" or simply distinguish between "firstborn" and "later born" children.

Birth order is commonly believed in pop psychology and popular culture to have a profound and lasting effect on psychological development and personality. For example, firstborns are seen as conservative and high achieving, middle children as natural mediators, and youngest children as charming and outgoing. In his book Born to Rebel, Frank Sulloway argues that firstborns are more conscientious, more socially dominant, less agreeable, and less open to new ideas compared to laterborns. Literature reviews that have examined many studies and attempted to control for confounding variables tend to find minimal effects for birth order on personality.^[2][3] 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.^[4]

Some research has found that firstborn children have slightly higher IQs on average than later born children.^[5] However, other research finds no such effect.^[6]

In practice, systematic birth order research is a challenge because it is difficult to control for all of the variables that are statistically related to birth order. For example, large families are generally lower in socioeconomic status than small families, so third born children are more likely than firstborn children to come from poorer families. Spacing of children, parenting style, and gender are additional variables to consider.

Regressive behavior at the birth of a new sibling [link]

The arrival of a new baby is especially stressful for firstborns and for siblings between 3 and 5 years old. Regressive behavior and aggressive behavior, such as handling the baby roughly, can also occur. All of these symptoms are considered to be typical and developmentally appropriate for children between the ages of 3–5.^{[citation needed]} While some can be prevented, the remainder can be improved within a few months. Regressive behavior may include demand for a bottle, thumb sucking, requests to wear diapers (even if toilet-trained), or requests to carry a security blanket.

Regressive behaviors are the child's way of demanding the parents' love and attention.

The American Academy of Pediatrics suggests^{[citation needed]} that instead of protesting or telling children to act their age, parents should simply grant their requests without becoming upset. The affected children will soon return to their normal routine when they realize that they now have just as important a place in the family as the new sibling. Most of the behaviors can be improved within a few months.

The University of Michigan Health System advises^{[citation needed]} 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.

Sibling rivalry [link]

Portrait of Lady Cockburn and her Three Eldest Sons, by Joshua Reynolds.

"Sibling rivalry" is a type of competition or animosity among brothers and sisters. It appears to be particularly intense when children are very close in age and of the same gender.^[7] Sibling rivalry can involve aggression; however, it is not the same as sibling abuse where one child victimizes another.

Sibling rivalry usually starts right after, or before, the arrival of the second child. While siblings will still love each other, it is not uncommon for them to bicker and be malicious to each other.^[8] Children are sensitive from the age of 1 year to differences in parental treatment and by 3 years they have a sophisticated grasp of family rules and can evaluate themselves in relation to their siblings.^[1] Sibling rivalry often continues throughout childhood and can be very frustrating and stressful to parents.^[9] One study found that the age group 10–15 reported the highest level of competition between siblings.^[10] Sibling rivalry can continue into adulthood and sibling relationships can change dramatically over the years. Approximately one-third of adults describe their relationship with siblings as rivalrous or distant. However, rivalry often lessens over time and at least 80% of siblings over age 60 enjoy close ties.^[1]

Each child in a family competes to define who they are as persons and want to show that they are separate from their siblings. Sibling rivalry increases when children feel they are getting unequal amounts of their parents' attention, where there is stress in the parents' and children's lives, and where fighting is accepted by the family as a way to resolve conflicts.^[9] 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.^[11] Evolutionary psychologists explain sibling rivalry in terms of parental investment and kin selection: a parent is inclined to spread resources equally among all children in the family, but a child wants most of the resources for him or herself.^[10]

Westermarck effect and its opposite [link]

Anthropologist Edvard Westermarck found that children who are brought up together as siblings are desensitized to form sexual attraction to one another later in life. This is known as the Westermarck Effect. 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.^[12][13]

The opposite phenomenon, when relatives do fall in love, is known as genetic sexual attraction. This can occur between siblings brought up apart from each other, for example, adoptees who are re-united in adulthood.

Famous sibling groups [link]

Two Sisters by William-Adolphe Bouguereau.

Brothers Prince Edward V of England and Prince Richard of Shrewsbury, 1st Duke of York.

The Brontë sisters, painted by their brother

• The Humboldt brothers naturalist Alexander Humboldt and philosopher Wilhelm von Humboldt
• The Grimm Brothers, folklorists and anthropologists
• The Strasser brothers, Otto Strasser and Gregor Strasser, leaders of a dissident brand of Naziism
• Intellectuals Julian Huxley, Aldous Huxley and their step brother Andrew Huxley of the famous Huxley family
• Kardashians, reality stars and American socialites, Kourtney Kardashian, Kim Kardashian, Khloe Kardashian and Rob Kardashian
• Jenners, reality stars, children of gold medal winning Olympic decathlete Bruce Jenner and half siblings of the Kardashians, Kendall Jenner, Kylie Jenner,Burt Jenner,Casey Jenner (b. June 10, 1980), Brandon Jenner (born June 4, 1981) and Brody Jenner (born August 21, 1983),(Half sibling of Kendall and Kyile).
• The Wayans Bros., is a family of directors, screenwriters and actors.
• Blue October, Justin and Jeremy Furstenfeld
• Olsen Brothers
• Olsen sisters, Mary-Kate and Ashley Olsen
• Smothers Brothers (Tom Smothers and Dick Smothers), comedians
• Wright Brothers (Orville Wright and Wilbur Wright), air travel pioneers and inventors
• The Dionne quintuplets
• Isabelle and Paul Duchesnay, world champion figure skaters.
• Sprouse brothers, American Actors, Dylan Sprouse and Cole Sprouse
• Sutter brothers, Canadian family who played or have been associated with the National Hockey League.
• Steve Waugh and Mark Waugh Australian cricketers.

Musicians [link]

• 30 Seconds to Mars, an American rock band, Jared and Shannon Leto
• A, an English rock band, Jason Perry & Adam Perry (identical twins) & Giles Perry
• AC/DC, an Australian rock band, Malcolm and Angus Young
• Architects, British rock band, Dan and Tom Searle (Twins)
• Arch Enemy, a Swedish melodic death metal band, Michael and Christopher Amott
• Beach Boys, an American rock band, Brian, Carl and Dennis Wilson
• BeBe & CeCe Winans, American gospel music brother and sister duo
• Biffy Clyro, A Scottish Rock Band, James Johnston & Ben Johnston (identical twins)
• Boards of Canada, are a Scottish electronic music duo consisting of brothers Mike Sandison and Marcus Eoin.
• Cavalera Conspiracy, a Brazilian heavy metal supergroup, Max and Igor Cavalera
• Cheeky Girls, a Romanian pop music duo, Gabriela and Monica Irimia
• Chevelle, an American rock trio, Pete, Sam and Joe Loeffler
• Creedence Clearwater Revival, an American rock band, John Fogerty and Tom Fogerty
• DEVO, an American new-wave band, Mark and Bob Mothersbaugh, and Gerald and Bob Casale
• Dixie Chicks, an American country music group Martie Maguire and Emily Robison
• Good Charlotte, an American pop punk band, Joel and Benji Madden
• Halestorm, an American hard rock band, Arejay and Lzzy Hale
• Hanson, an American pop rock band, Isaac, Taylor, and Zac Hanson
• Heart, an American rock band, Ann and Nancy Wilson
• Jackson 5, an American popular music family group, Jackie, Tito, Jermaine, Marlon and Michael Jackson (And also Randy when Jermaine left.)
• Jonas Brothers, an American Disney Rock band, Kevin, Joe, and Nick Jonas
• Kalmah, a Finnish melodic death metal band, Pekka and Antti Kokko.
• Kings of Leon, an American rock band, Caleb, Nathan and Jared Followill
• Lamb of God, an American metal band, Will and Chris Adler
• Madina Lake, an American rock band, Nathan Leone & Matthew Leone (identical twins)
• Misery Signals, an American hardcore band, Brandon and Ryan Morgan
• My Chemical Romance, an American rock band, Mikey and Gerard Way
• Naked Brothers Band an American rock band Alex Wolff and Nat Wolff
• Nickleback, a Canadian rock band, Chad, Mike and Brandon Kroeger
• No Doubt, an American rock band, Gwen and Eric Stefani
• Oasis, an English rock band, Liam and Noel Gallagher
• Pantera, an American heavy metal band, Dimebag Darrell and Vinnie Paul
• Paramore, an American rock band, Josh and Zac Farro
• Pierce the Veil, an American experimental post-hardcore band, Vic and Mike Fuentes
• Radiohead, an English alternative rock band, Jonny and Colin Greenwood
• Rufus Wainwright & Martha Wainwright
• Stone Temple Pilots, an American grunge/alternative rock band, Robert and Dean DeLeo
• Tegan and Sara, Canadian indie band, Tegan Rain and Sara Kiersten Quin
• The Allman Brothers Band, an American southern jam band led by Gregg Allman and the late Duane Allman.
• The Andrews Sisters, an American close harmony singing group, LaVerne Sophia, Maxene Angelyn and Patricia "Patty" Marie Andrews
• The Bee Gees, a British harmonic "soft rock" act, Barry, Robin and Maurice Gibb
• The Boswell Sisters, an American close harmony singing group, Martha Connee and Helvetia "Vet" Boswell
• The Maccabees, British indie rock band, brothers Felix, Hugo and Will White
• The Burns Sisters, folk/pop/rock trio with a Celtic slant
• The Cribs, indie rock band, Gary Jarman, Ryan Jarman (identical twins) & Ross Jarman
• The Corrs, a Celtic folk rock band, Andrea, Sharon, Caroline and Jim Corr
• The Cowsills, an American popular music family band. Bill, Bob, Paul, Barry, John, Susan and Mom, Barbara.
• The Darkness, an English rock band, Justin Hawkins and Dan Hawkins.
• The Everly Brothers, an American country-influenced band, Philip and Isaac Donald Everly.
• The Hives, Swedish Rock Band, Pelle Almqvist & Niklas Almqvist
• The Kinks, an English rock band, Ray and Dave Davies
• The Magic Numbers, an English rock band, Angela Gannon & Sean Gannon/Michele Stodart & Romeo Stodart
• The Osmonds, an American family music group, Alan, Wanyne, Merrill, Jay, Donny, Marie and Jimmy Osmond
• The Proclaimers, A Scottish Vocal Band, Charlie Reid & Craig Reid
• The Veronicas, an Australian electropop pop-rock duo, Jessica and Lisa Origliasso
• Tokio Hotel, a German pop rock band, Bill and Tom Kaulitz
• UB40, an English reggae band, Ali Campbell and Robin Campbell
• Van Halen, an American heavy metal/hard rock band, Eddie, Wolfgang and Alex Van Halen
• Wilson Phillips, an American pop group composed of sisters Wendy and Carnie Wilson, with Chynna Phillips
• YU grupa a Serbian rock band Dragi Jelic, Zika Jelic and Petar Jelic
• Young Guns, British rock band, brothers John and Fraser Taylor

See also [link]

• Sibling relationship
• Cousin

Notes [link]

External links [link]

Wikiquote has a collection of quotations related to: Siblings

Wikimedia Commons has media related to: Brothers

Wikimedia Commons has media related to: Sisters

Look up sibling in Wiktionary, the free dictionary.

•  Chisholm, Hugh, ed. (1911). "sister". Encyclopædia Britannica (11th ed.). Cambridge University Press.