Monozygotic ("identical") twins

A twin is one of two offspring produced in the same pregnancy.^[1] Twins can either be monozygotic ("identical"), meaning that they develop from one zygote that splits and forms two embryos, or dizygotic ("fraternal") because they develop from two separate eggs that are fertilized by two separate sperm.

In contrast, a fetus which develops alone in the womb is called a singleton, and the general term for one offspring of a multiple birth is multiple.

Statistics[link]

The twin birth rate in the United States rose 76 percent from 1980 through 2009, from 18.9 to 33.3 per 1,000 births.^[2] The Yoruba have the highest rate of twinning in the world, at 45-50 twin sets (or 90-100 twins) per 1,000 live births,^[3][4][5] possibly because of high consumption of a specific type of yam containing a natural phytoestrogen which may stimulate the ovaries to release an egg from each side.^[6][7]

The world's highest rates of twinning are found across Central Africa, where there are 18-30 twin sets (or 37-62 twins) per 1,000 live births.^[8] In Latin-America and South Asia and South-East Asia the lowest rates are found; only 6-9 twin sets per 1,000 live births. North America and Europe have intermediate rates of 9–16 twin sets per 1,000 live births.^[8]

Due to the limited size of the mother's womb, multiple pregnancies are much less likely to carry to full term than single births, with twin pregnancies lasting only 37 weeks (3 weeks less than full term) on average.^[9]

Women who have a family history of fraternal twins have a higher chance of producing fraternal twins themselves, as there is a genetically linked tendency to hyper-ovulate. There is no known genetic link for identical twinning.^[10] Other factors that increase the odds of having fraternal twins include maternal age, fertility drugs and other fertility treatments, nutrition, and prior births.^[11]

Zygosity[link]

Zygosity is the degree of identity in the genome of twins. There are five common variations of twinning. The three most common variations are all dizygotic (fraternal):

• Male–female twins are the most common result, 50 percent of dizygotic twins and the most common grouping of twins.
• Female–female dizygotic twins (sometimes called "sororal twins")
• Male–male dizygotic twins

The other two variations are monozygotic ("identical") twins:

• Female–female monozygotic twins
• Male–male monozygotic twins (less common)

Among non-twin births, male singletons are slightly (about five percent) more common than female singletons. The rates for singletons vary slightly by country. For example, the sex ratio of birth in the US is 1.05 males/female,^[12] while it is 1.07 males/female in Italy.^[13] However, males are also more susceptible than females to death in utero, and since the death rate in utero is higher for twins, it leads to female twins being more common than male twins.

Fraternal/Sororal (dizygotic) twins[link]

Eight-month-old sororal twin girls napping

Actresses Mary-Kate and Ashley Olsen, possibly the best-known dizygotic twins.

Fraternal or dizygotic (DZ) twins (also referred to as "non-identical twins", "dissimilar twins", "biovular twins", and, in cases of females, sororal twins) usually occur when two fertilized eggs are implanted in the uterus wall at the same time. When two eggs are independently fertilized by two different sperm cells, fraternal twins result. The two eggs, or ova, form two zygotes, hence the terms dizygotic and biovular.

Dizygotic twins, like any other siblings, have an extremely small chance of having the same chromosome profile. Like any other siblings, dizygotic twins may look similar, particularly given that they are the same age. However, dizygotic twins may also look very different from each other. They may be of different sexes or the same sex. The same holds true for brothers and sisters from the same parents, meaning that fraternal and/or sororal twins are simply siblings who happen to be the same age.

Studies show that there is a genetic basis for dizygotic twinning. However, it is only their mother that has any effect on the chances of having such twins; there is no known mechanism for a father to cause the release of more than one ovum. Dizygotic twinning ranges from six per thousand births in Japan (similar to the rate of monozygotic twins) to 14 and more per thousand in some African countries.^[6]

Dizygotic twins are also more common for older mothers, with twinning rates doubling in mothers over the age of 35.^[14] With the advent of technologies and techniques to assist women in getting pregnant, the rate of fraternals has increased markedly.

Monozygotic ("identical") twins[link]

Comparison of zygote development in monozygotic and dizygotic twins. In the uterus, a majority of monozygotic twins (60–70%) share the same placenta but have separate amniotic sacs. In 18–30% of monozygotic twins each fetus has a separate placenta and a separate amniotic sac. A small number (1–2%) of monozygotic twins share the same placenta and amniotic sac. Fraternal twins each have their own placenta and own amniotic sac.

Monozygotic (MZ) or identical twins occur when a single egg is fertilized to form one zygote (hence, "monozygotic") which then divides into two separate embryos.

Mechanism[link]

Regarding spontaneous or natural monozygotic twinning, a recent theory posits that monozygotic twins are formed after a blastocyst essentially collapses, splitting the progenitor cells (those that contain the body's fundamental genetic material) in half, leaving the same genetic material divided in two on opposite sides of the embryo. Eventually, two separate fetuses develop.^[15] Spontaneous division of the zygote into two embryos is not considered to be a hereditary trait, but rather a spontaneous or random event.^[14][16]

Monozygotic twins may also be created artificially by embryo splitting. It can be used as an expansion of IVF to increase the number of available embryos for embryo transfer.^[17]

Incidence[link]

Monozygotic twinning occurs in birthing at a rate of about three in every 1000 deliveries worldwide.^[16]

The likelihood of a single fertilization resulting in monozygotic twins is uniformly distributed in all populations around the world.^[14] This is in marked contrast to dizygotic twinning, which ranges from about six per thousand births in Japan (almost similar to the rate of identical twins, which is around 4–5) to 15 and more per thousand in some parts of India^[18] and up to over 20 in some Central African countries.^[8] The exact cause for the splitting of a zygote or embryo is unknown.

In-vitro fertilization techniques are more likely to create dizygotic twins. Only about three pairs of twins per 1,000 deliveries occur as a result of natural conception, while for IVF deliveries, there are nearly 21 pairs of twins for every 1,000.^[19]

Genetic and epigenetic similarity[link]

Monozygotic twins are genetically nearly identical and they are always the same sex unless there has been a mutation during development. The children of monozygotic twins test genetically as half-siblings (or full siblings, if monozygotic twin sisters reproduce with monozygotic twin brothers, or if monozygotic twin brothers reproduce with the same woman), rather than first cousins. Identical twins do not have the same fingerprints, due to the fact that even in a small space inside the womb, people have contact with different parts of this environment, which gives small variations in the same digital, making them unique.^{[citation needed]} On rare occasions, monozygotic twins may express different phenotypes, normally due to an environmental factor or the deactivation of different X chromosomes in female monozygotic twins, and in some extremely rare cases, due to aneuploidy, twins may express different sexual phenotypes, normally from an XXY Klinefelter's syndrome zygote splitting unevenly.^[20][21]

Even with nearly identical DNA, epigenetic modification, caused by differing environmental influences throughout their lives, affects which genes are switched on or off. A study of 80 pairs of human monozygotic twins ranging in age from three to 74 showed that the youngest twins have relatively few epigenetic differences. The number of epigenetic differences increases with age. Fifty-year-old twins had over three times the epigenetic difference of three-year-old twins. Twins who had spent their lives apart (such as those adopted by two different sets of parents at birth) had the greatest difference.^[22] However, certain characteristics become more alike as twins age, such as IQ and personality. This phenomenon illustrates the influence of genetics in many aspects of human characteristics and behavior.^[23][24][25]

Semi-identical twins[link]

Half-identical or semi-identical twins (also referred to as "half twins") are the result of a very rare form of twinning in which the twins inherit exactly the same genes from their mother but different genes from their father. Although examples of half-identical twins have been found, the exact mechanism of their conception is not well-understood, but could theoretically occur in polar body twinning where sperm cells fertilize both the ovum and the second polar body.

This situation is not the same as the common form of fraternal twinning, in which two genetically different ova are fertilized by two genetically different sperm. In this case, the ova are genetically identical.

Types[link]

There are two mechanisms by which this might happen:

• Polar twins (or "polar body twins"), where two sperm fertilize an ovum, one of the two fertilizing a polar body;^[26] or where an ovum splits into identical copies, one containing a polar body, prior to fertilization, allowing it to be fertilized by two different sperm.^[27][28]
• Sesquizygotic twins, where two sperm fertilize the one ovum, forming a triploid, and then splitting.^[29]

A 1981 study of a deceased triploid XXX twin fetus without a heart showed that although its fetal development suggested that it was an identical twin, as it shared a placenta with its healthy twin, tests revealed that it was likely a polar body twin. The authors were unable to predict whether a healthy fetus could result from a polar body twinning.^[30] In 2003 a study argued that many cases of triploidity arise from semi-identical twinning.^[31] In 2007, a study reported a case of a pair of living twins, one a hermaphrodite and one a phenotypical male. The twins were both found to be chimeras and to share all of their maternal DNA but only half of their father's DNA. The exact mechanism of fertilization could not be determined but the study stated that it was unlikely to be a case of polar body twinning.^[32]

Degree of separation[link]

Various types of chorionicity and amniosity (how the baby's sac looks) in monozygotic (one egg/identical) twins as a result of when the fertilized egg divides

Dichorionic diamniotic twins in the 4th week after fertilization

The degree of separation of the twins in utero depends on if and when they split into two zygotes. Dizygotic twins were always two zygotes. Monozygotic twins split into two zygotes at some time very early in the pregnancy. The timing of this separation determines the chorionicity and amniocity (the number of sacs) of the pregnancy. Dichorionic twins either never divided (i.e.: were dizygotic) or they divided within the first 4 days. Monoamnionic twins divide after the first week.

In very rare cases, twins become conjoined twins. Furthermore, there can be various degrees of shared environment of twins in the womb, potentially leading to pregnancy complications.

It is a common misconception that two placentas means twins are dizygotic. But if monozygotic twins separate early enough, the arrangement of sacs and placentas in utero is indistinguishable from dizygotic twins.

Demographics[link]

A recent study has found that insulin-like growth factor present in dairy products may increase the chance of dizygotic twinning. Specifically, the study found that vegan mothers (who exclude dairy from their diets) are one-fifth as likely to have twins as vegetarian or omnivore mothers, and concluded that "Genotypes favoring elevated IGF and diets including dairy products, especially in areas where growth hormone is given to cattle, appear to enhance the chances of multiple pregnancies due to ovarian stimulation."^[39]

From 1980–97, the number of twin births in the United States rose 52%.^[40] This rise can at least partly be attributed to the increasing popularity of fertility drugs like Clomid and procedures such as in vitro fertilization, which result in multiple births more frequently than unassisted fertilizations do. It may also be linked to the increase of growth hormones in food.^[39]

Ethnicity[link]

About 1 in 90 human births (1.1%) results from a twin pregnancy.^[41] The rate of dizygotic twinning varies greatly among ethnic groups, ranging as high as about 45 per 1000 births for the Yoruba to 10% for Linha São Pedro, a tiny Brazilian settlement which belongs to the city of Cândido Godói.^[42] In Cândido Godói, one in five pregnancies has resulted in twins.^[43] The Argentine historian Jorge Camarasa has put forward a theory that experiments of the Nazi doctor Josef Mengele could be responsible for the high ratio of twins in the area.^[44] His theory was rejected by Brazilian scientists who had studied twins living in Linha São Pedro; they suggested genetic factors within that community as a more likely explanation.^[45] A high twinning rate has also been observed in other places of the world, including Igbo-Ora in Nigeria^[46] and Kodinji in India.^[47]

The widespread use of fertility drugs causing hyperovulation (stimulated release of multiple eggs by the mother) has caused what some call an "epidemic of multiple births". In 2001, for the first time ever in the US, the twinning rate exceeded 3% of all births. Nevertheless, the rate of monozygotic twins remains at about 1 in 333 across the globe.

In a study on the maternity records of 5750 Hausa women living in the Savannah zone of Nigeria, there were 40 twins and 2 triplets per 1000 births. Twenty-six percent of twins were monozygous. The incidence of multiple births, which was about five times higher than that observed in any western population, was significantly lower than that of other ethnic groups, who live in the hot and humid climate of the southern part of the country. The incidence of multiple births was related to maternal age but did not bear any association to the climate or prevalence of malaria.^[48]

Predisposing factors[link]

The predisposing factors of monozygotic twinning are unknown.

Dizygotic twin pregnancies are slightly more likely when the following factors are present in the woman:

• She is of West African descent (especially Yoruba)
• She is between the age of 30 and 40 years
• She is greater than average height and weight
• She has had several previous pregnancies.

Women undergoing certain fertility treatments may have a greater chance of dizygotic multiple births. This can vary depending on what types of fertility treatments are used. With in vitro fertilization (IVF), this is primarily due to the insertion of multiple embryos into the uterus. Some other treatments such as the drug Clomid can stimulate a woman to release multiple eggs, increasing the likelihood of multiples.

Delivery interval[link]

A 15-year German study^[49] of 8,220 vaginally delivered twins (that is, 4,110 pregnancies) in Hesse yielded a mean delivery time interval of 13.5 minutes.^[50] The delivery interval between the twins was measured as follows:

• Within 15 minutes: 75.8%
• 16-30 minutes: 16.4%
• 31-45 minutes: 4.3%
• 46-60 minutes: 1.7%
• Over 60 minutes: 1.8% (72 instances)

The study stated that the occurrence of complications "was found to be more likely with increasing twin-to-twin delivery time interval" and suggested that the interval be kept short, though it noted that the study did not examine causes of complications and did not control for factors such as the level of experience of the obstetrician, the wish of the women giving birth, or the "management strategies" of the procedure of delivering the second twin.

Complications of twin pregnancy[link]

Vanishing twins[link]

Researchers suspect that as many as 1 in 8 pregnancies start out as multiples, but only a single fetus is brought to full term, because the other has died very early in the pregnancy and has not been detected or recorded.^[51] Early obstetric ultrasonography exams sometimes reveal an "extra" fetus, which fails to develop and instead disintegrates and vanishes. This is known as vanishing twin syndrome.

Chang and Eng Bunker, born in Siam (now Thailand) in 1811, were the origin of the term "Siamese twins".

Conjoined twins[link]

Conjoined twins (or the deprecated term "siamese") are monozygotic twins whose bodies are joined together during pregnancy. This occurs where the single zygote of MZ twins fails to separate completely, and the zygote starts to split after day 12^[33] following fertilization. This condition occurs in about 1 in 50,000 human pregnancies. Most conjoined twins are now evaluated for surgery to attempt to separate them into separate functional bodies. The degree of difficulty rises if a vital organ or structure is shared between twins, such as the brain, heart or liver.

Chimerism[link]

A chimera is an ordinary person or animal except that some of their parts actually came from their twin or from the mother. A chimera may arise either from monozygotic twin fetuses (where it would be impossible to detect), or from dizygotic fetuses, which can be identified by chromosomal comparisons from various parts of the body. The number of cells derived from each fetus can vary from one part of the body to another, and often leads to characteristic mosaicism skin coloration in human chimeras. A chimera may be intersex, composed of cells from a male twin and a female twin.

Parasitic twins[link]

Sometimes one twin fetus will fail to develop completely and continue to cause problems for its surviving twin. One fetus acts as a parasite towards the other. Sometimes the parasitic twin becomes an almost indistinguishable part of the other, and sometimes this needs to be medically dealt with.

Partial molar twins[link]

A very rare type of parasitic twinning is one where a single viable twin is endangered when the other zygote becomes cancerous, or molar. This means that the molar zygote's cellular division continues unchecked, resulting in a cancerous growth that overtakes the viable fetus. Typically, this results when one twin has either triploidy or complete paternal uniparental disomy, resulting in little or no fetus and a cancerous, overgrown placenta, resembling a bunch of grapes.

Miscarried twin[link]

Occasionally, a woman will suffer a miscarriage early in pregnancy, yet the pregnancy will continue; one twin was miscarried but the other was able to be carried to term. This occurrence is similar to the vanishing twin syndrome, but typically occurs later, as the twin is not reabsorbed.

Low birth weight[link]

Twins typically suffer from the lower birth weights and greater likelihood of prematurity that is more commonly associated with the higher multiple pregnancies.

Twin-to-twin transfusion syndrome[link]

Monozygotic twins who share a placenta can develop twin-to-twin transfusion syndrome. This condition means that blood from one twin is being diverted into the other twin. One twin, the 'donor' twin, is small and anemic, the other, the 'recipient' twin, is large and polycythemic. The lives of both twins are endangered by this condition.

Human twin studies[link]

Twin studies are utilized in an attempt to determine how much of a particular trait is attributable to either genetics or environmental influence. These studies compare monozygotic and dizygotic twins for medical, genetic, or psychological characteristics to try to isolate genetic influence from epigenetic and environmental influence. Twins that have been separated early in life and raised in separate households are especially sought-after for these studies, which have been used widely in the exploration of human nature. However, the utility and accuracy of these twin studies has been called into question and remains controversial. Classical twin studies have are now being supplemented with molecular genetic studies which identify individual genes.

Unusual twinnings[link]

Among dizygotic twins, in rare cases, the eggs are fertilized at different times with two or more acts of sexual intercourse, either within one menstrual cycle (superfecundation) or, even more rarely, later on in the pregnancy (superfetation). This can lead to the possibility of a woman carrying fraternal twins with different fathers (that is, half-siblings). This phenomenon is known as heteropaternal superfecundation. One 1992 study estimates that the frequency of heteropaternal superfecundation among dizygotic twins whose parents were involved in paternity suits was approximately 2.4%; see the references section, below, for more details.

Dizygotic twins from biracial couples can sometimes be mixed twins, which exhibit differing ethnic and racial features. One such pairing was born in Germany in 2008 to a white father from Germany and a black mother from Ghana.^[52][53]

Heterotopic pregnancy is an exceedingly rare type of dizygotic twinning in which one twin implants in the uterus as normal and the other remains in the fallopian tube as an ectopic pregnancy. Ectopic pregnancies must be resolved because they can be life-threatening to the mother. However, in most cases, the intrauterine pregnancy can be salvaged.

Among monozygotic twins, in extremely rare cases, twins have been born with different sexes (one male, one female).^[54] There can be identical boy/girl twins if the sex gene of the embryo has an extra x chromosome (the fertilized egg would be an xxy) then when the egg splits one can have xx (girl) genes and one can have xy (boy) genes. This is rare, but possible. Records show there are only 4 known cases of these type twins. The probability of this is so vanishingly small that multiples having different sexes is universally accepted as a sound basis for a clinical determination that in utero multiples are not monozygotic. When monozygotic twins are born with different sexes it is because of chromosomal birth defects. In this case, although the twins did come from the same egg, it is incorrect to refer to them as genetically identical, since they have different karyotypes.

Semi-identical twins[link]

Monozygotic twins can develop differently, due to different genes being activated.^[55] More unusual are "semi-identical twins". These "half-identical twins" are hypothesized to occur when an unfertilized egg cleaves into two identical attached ova and which are viable for fertilization. Both cloned ova are then fertilized by different sperm and the coalesced eggs undergo further cell duplications developing as a chimeric blastomere. If this blastomere then undergoes a twinning event, two embryos will be formed, each of which have different paternal genes and identical maternal genes.

This results in a set of twins with identical genes from the mother's side, but different genes from the father's side. Cells in each fetus carry genes from either sperm, resulting in chimeras. This form had been speculated until only recently being recorded in western medicine.^[56][57][58]

Twin calves of the Hereford breed

Animal twins[link]

Twins are common in many animal species, such as cats, sheep, ferrets, dogs and deer. The incidence of twinning among cattle is about 1–4%, and research is under way to improve the odds of twinning, which can be more profitable for the breeder if complications can be sidestepped or managed. A female calf that is the twin of a bull becomes partially masculinized and is known as a freemartin. The nine-banded armadillo (Dasypus novemcinctus) has identical twins (usually four babies) as its regular reproduction and not as exceptional cases.^[59][60]

See also[link]

Wikimedia Commons has media related to: Twin

Look up twin in Wiktionary, the free dictionary.

• Conjoined twins
• Doppelgänger
• Gemini (astrology)
• Incest between twins
• List of multiple births
• List of twins
• Litter (animal)
• Look-alike
• Multiple birth
• Twins in mythology

References[link]

Further reading[link]

• Bacon, Kate. Twins in Society: Parents, Bodies, Space, and Talk (Palgrave Macmillan; 2010) 221 pages; explores the experience of child twins, adult twins, and parents of twins, with a focus on Britain.
• Nieuwint, Aggie; Rieteke Van Zalen-Sprock, Pieter Hummel, Gerard Pals, John Van Vugt, Hans Van Der Harten, Yvonne Heins and Kamlesh Madan (1999). "'Identical' twins with discordant karyotypes". Prenatal Diagnosis 19 (1): 72–6. DOI:10.1002/(SICI)1097-0223(199901)19:1<72::AID-PD465>3.0.CO;2-V. PMID 10073913. 
• Wenk RE, Houtz T, Brooks M, Chiafari FA (1992). "How frequent is heteropaternal superfecundation?". Acta geneticae medicae et gemellologiae 41 (1): 43–7. PMID 1488855. 
• Girela, Eloy; Jose A. Lorente, J. Carlos Alvarez, Maria D. Rodrigo, Miguel Lorente and Enrique Villanueva (1997). "Indisputable double paternity in dizygous twins". Fertility and Sterility 67 (6): 1159–61. DOI:10.1016/S0015-0282(97)81456-2. PMID 9176461. 
• Shinwell ES, Reichman B, Lerner-Geva L, Boyko V, Blickstein I (September 2007). ""Masculinizing" effect on respiratory morbidity in girls from unlike-sex preterm twins: a possible transchorionic paracrine effect". Pediatrics 120 (3): e447–53. DOI:10.1542/peds.2006-3574. PMID 17766488. http://pediatrics.aappublications.org/cgi/pmidlookup?view=long&pmid=17766488. Retrieved 2008-10-06. 
• Lummaa V, Pettay JE, Russell AF (June 2007). "Male twins reduce fitness of female co-twins in humans". Proceedings of the National Academy of Sciences of the United States of America 104 (26): 10915–20. DOI:10.1073/pnas.0605875104. PMC 1904168. PMID 17576931. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=17576931. Retrieved 2008-10-06. 
• Schein, Elyse; Paula Bernstein (2007). Identical Strangers: A Memoir of Twins Separated and Reunited. New York: Random House. ISBN 1-4000-6496-1. OCLC 123390922. 
• Helle, Samuli; Virpi Lummaa and Jukka Jokela (2004). "Selection for Increased Brood Size in Historical Human Populations" (PDF). Evolution 58 (2): 430–436. DOI:10.1111/j.0014-3820.2004.tb01658.x. PMID 15068359. http://www.huli.group.shef.ac.uk/helleevolution2004.pdf. Retrieved 2008-10-02. 
• "TWINS Guide to the First Year" (PDF). Fort Collins, Colorado: TWINS Magazine. 2008. http://www.twinsmagazine.com/media/images/Guide2008.pdf. Retrieved 2008-10-06. 
• Samson, Jennifer. "Facts About Multiples: An Encyclopedia of Multiple Birth Records". http://www3.telus.net/tyee/multiples/index.html. Retrieved 2008-10-18. 
• Am J Med Genet C Semin Med Genet. 2009 May 15;151C(2):136-41. Not really identical: epigenetic differences in monozygotic twins and implications for twin studies in psychiatry. Haque FN, Gottesman II, Wong AH.

Justin Bieber
Justin Bieber at the NRJ Music Awards in Cannes, France in 2012
Background information
Birth name	Justin Drew Bieber[1]
Born	(1994-03-01) March 1, 1994 (age 18)[2] London, Ontario, Canada
Origin	Stratford, Ontario, Canada
Genres	Pop, R&B, teen pop[3][4][5]
Occupations	Singer-songwriter, musician, actor
Instruments	Vocals, guitar, piano, percussion,[6] trumpet[7]
Years active	2008–present
Labels	Island, RBMG
Associated acts	Usher, Ludacris
Website	justinbiebermusic.com

Justin Drew Bieber ( /ˈbiːbər/ BEE-bər, born March 1, 1994)^[2] is a Canadian Pop/R&B singer-songwriter, musician, and actor.^[3][5] Bieber was discovered in 2008 by Scooter Braun,^[8] who came across Bieber's videos on YouTube and later became his manager. Braun arranged for him to meet with Usher in Atlanta, Georgia, and Bieber was soon signed to Raymond Braun Media Group (RBMG), a joint venture between Braun and Usher,^[9] and then to a recording contract with Island Records offered by L.A. Reid.^[6][10] Bieber's debut single, "One Time", was released in 2009 and peaked in the top twenty in Canada and charted in the top thirty in several international markets. His debut album, the seven-track EP My World, followed in November 2009, and was soon certified platinum in the United States. He became the first artist to have seven songs from a debut album chart on the Billboard Hot 100.^[11]

Bieber's first full-length studio album, My World 2.0, was released in March 2010. It debuted at number one or within the top ten in several countries and was certified platinum in the United States. It was preceded by the worldwide top-ten single, "Baby". The music video of "Baby" is currently ranked as the most viewed and most discussed YouTube video.^[12] Bieber followed up the release of his debut album with his first headlining tour, the My World Tour, the remix albums My Worlds Acoustic and Never Say Never – The Remixes, and the 3D biopic-concert film Justin Bieber: Never Say Never, that nearly matched the record for the biggest opening weekend gross for a concert-film. Bieber released his second studio album, Under the Mistletoe, in November 2011, which debuted at number one on the Billboard 200. Bieber has received numerous awards, including Artist of the Year at the 2010 American Music Awards, and has been nominated for such awards as Best New Artist and Best Pop Vocal Album at the 53rd Grammy Awards. In 2012, Bieber was named Forbes 3rd most powerful celebrity in the world, earning $55 million. As of May 2012, Bieber has sold 15 million albums.^[13]

Early life[link]

Bieber was born on March 1, 1994, in London, Ontario in St Joseph's Hospital,^[14][15] and was raised in Stratford, Ontario.^[16] Bieber's mother, Patricia Lynn "Pattie" Mallette, was 18 years old when she became pregnant. Mallette, originally from Stratford, raised her son with the help of her parents, Bruce and Diane.^[17] Mallette worked a series of low-paying office jobs, raising Bieber as a single mother in low-income housing. Bieber has maintained contact with his father, Jeremy Jack Bieber, who married another woman and had two children.^[18][19][20] Bieber's great-grandfather was from Germany.^[21] Bieber's mother's ancestry is French Canadian.^[22] Bieber attended a French immersion elementary school in Stratford called Jeanne Sauvé Catholic School.^[17]

During his childhood, Bieber was interested in hockey, soccer, and chess; he often kept his musical aspirations to himself.^[18] As he grew up, Bieber taught himself to play the piano, drums, guitar, and trumpet.^[16][23] In early 2007, when he was twelve, Bieber sang Ne-Yo's "So Sick" for a local singing competition in Stratford and was placed second.^[6][23] Mallette posted a video of the performance on YouTube for their family and friends to see. She continued to upload videos of Bieber singing covers of various R&B songs, and Bieber's popularity on the site grew.^[10] Chris Hicks, Bieber's A&R at Island/Def Jam, explained the young artist's huge online following to HitQuarters by saying:

"He was doing something different. He was an attractive white kid singing very soulful R&B hits. That set him apart immediately from anyone in his range because no one was covering or singing these kind of records. But equally important was that you believed in these songs – it was real. And you wanted to hear more."^[24]

Career[link]

[edit] 2008–09: Discovery and My World

While searching for videos of a different singer, Scooter Braun, a former marketing executive of So So Def, clicked on one of Bieber's 2007 videos by accident.^[18] Impressed, Braun tracked down the theater Bieber was performing in, located Bieber's school, and finally contacted Mallette. Mallette was reluctant because of Braun's Jewish religion; she remembered praying, "God, I gave him to you. You could send me a Christian man, a Christian label! ... you don’t want this Jewish kid to be Justin’s man, do you?"^[18] However, after praying with her church elders and receiving their encouragement, she permitted Braun to fly Bieber, then 13,^[10] to Atlanta, Georgia, to record demo tapes.^[18] A week after arriving, Bieber sang for R&B singer/songwriter Usher.^[25] Bieber was soon signed to Raymond Braun Media Group (RBMG), a joint venture between Braun and Usher.^[9] Justin Timberlake was also reportedly in the running to sign Bieber, but lost the bidding war to Usher.^[9][26] Usher then sought assistance in finding a label home for the artist from then manager Chris Hicks, who helped engineer an audition with his contact Antonio L.A. Reid of Island Def Jam Music Group.^[24] Reid signed Bieber to Island Records in October 2008 (resulting in a joint venture between RBMG and Island Records) and appointed Hicks as executive Vice-President of Def Jam where he would be able manage Bieber's career at the label.^{[6][9][10][24]} At that point, Bieber and his mother moved to Atlanta temporarily, also the home of Usher and Braun, to record and get counseling from Braun.^[9] Braun became Bieber's manager.^[10]

Bieber in September 2009 at the Nintendo World Store

Bieber's first single, "One Time", was released to radio while Bieber was still recording his debut album.^[27] The song reached number 12 on the Canadian Hot 100 during its first week of release in July 2009,^[10] and later peaked at number 17 on the Billboard Hot 100. During fall 2009 it had success in international markets.^[28] The song was certified Platinum in Canada and the US and Gold in Australia and New Zealand.^[29][30][31] Bieber's first release, an extended play entitled My World, was released on November 17, 2009. The album's second single, "One Less Lonely Girl", and two promo singles, "Love Me", and "Favorite Girl", were released exclusively on the iTunes store and charted within the top forty of the Billboard Hot 100.^[28] "One Less Lonely Girl" was later also released to radio and peaked within the top fifteen in Canada and the US, being certified Gold in the latter.^[28] My World was eventually certified Platinum in the US and Double Platinum in both Canada and the UK.^[31][32][33] To promote the album, Bieber performed on several live shows such as mtvU's VMA 09 Tour, European program The Dome, YTV's The Next Star, The Today Show,^[34][35] The Wendy Williams Show, Lopez Tonight, The Ellen DeGeneres Show, It's On with Alexa Chung, Good Morning America, Chelsea Lately, and BET's 106 & Park with Rihanna. Bieber also guest starred in an episode of True Jackson, VP in late 2009.^[36]

Bieber performed Stevie Wonder's "Someday at Christmas" for U.S. President Barack Obama and first lady Michelle Obama at the White House for Christmas in Washington, which was broadcast on December 20, 2009, on U.S. television broadcaster TNT.^[37] Bieber was also one of the performers at Dick Clark's New Year's Rockin' Eve with Ryan Seacrest on December 31, 2009.^[38] Bieber was a presenter at the 52nd Grammy Awards on January 31, 2010. He was invited to be a vocalist for the remake of We Are The World (a song written by Michael Jackson and Lionel Richie) for its 25th anniversary to benefit Haiti after the earthquake. Bieber sings the opening line, which was sung by Lionel Richie in the original version.^[39] On March 12, 2010, a version of K'naan's "Wavin' Flag" recorded by a collective of Canadian musicians known as Young Artists for Haiti was released. Bieber is featured in the song, performing the closing lines.

[edit] 2010–11: My World 2.0 and Never Say Never film

"Baby", the lead single from his debut album, My World 2.0, which features Ludacris, was released in January 2010 and became his biggest hit thus far, charting at number five in the U.S. and reaching the top ten in seven other countries.^[28] Two promo singles "Never Let You Go", and "U Smile" were top thirty hits on the U.S. Hot 100, and top twenty hits in Canada.^[28] According to review aggregator Metacritic, the album has received "generally favorable reviews".^[40] It debuted at number one on the U.S. Billboard 200, making Bieber the youngest solo male act to top the chart since Stevie Wonder in 1963.^[41] My World 2.0 also debuted at number one on the Canadian Albums Chart, Irish Albums Chart, Australian Albums Chart, and the New Zealand Albums Chart^[28] and reached the top ten of fifteen other countries.^[42][43] To promote the album, Bieber appeared on several live programs including The View, the 2010 Kids Choice Awards, Nightline, The Late Show with David Letterman, The Dome and 106 and Park.^[44] Bieber collaborated with Sean Kingston on his single "Eenie Meenie" which also appeared on Bieber's debut album. The song reached the top ten in the United Kingdom and Australia, and the top-twenty of most other markets.

Bieber performing at the Conseco Fieldhouse, in August 2010

On April 10, 2010, Bieber was the musical guest on Saturday Night Live.^[45] On July 4, 2010, Bieber performed at the Macy's Fourth of July Fireworks Spectacular in New York City.^[46] The second single from My World 2.0, "Somebody to Love", was released in April 2010, and a remix was released featuring Bieber's mentor Usher. The single reached number ten in Canada, number fifteen in the United States, and the top twenty in multiple international countries.

On June 23, 2010, Bieber went on his first official headlining tour, the My World Tour, starting in Hartford, Connecticut, to promote My World and My World 2.0.^[47] In July 2010, it was reported that Bieber was the most searched for celebrity on the Internet.^[48] That same month his music video, "Baby", surpassed Lady Gaga's "Bad Romance" to become the most viewed, and most disliked YouTube video ever.^[49] In September 2010, it was reported that Bieber accounted for three percent of all traffic on Twitter, according to an employee of the social-networking site.^[50]

Bieber began recording his second album in July 2010 in New York City.^[51] At this point, because of puberty, his voice was deeper than it was when he recorded his first album. In April 2010, the singer discussing his vocals remarked, "It cracks. Like every teenage boy, I'm dealing with it and I have the best vocal coach in the world. [...] Some of the notes I hit on "Baby" I can't hit anymore. We have to lower the key when I sing live."^[52]

Bieber performing in Jakarta during his My World Tour.

Bieber guest-starred in the season premiere of the CBS crime drama CSI: Crime Scene Investigation, which aired on September 23, 2010. He played a "troubled teen who is faced with a difficult decision regarding his only brother", who is also a serial bomber. Bieber was also in a subsequent episode which aired on February 17, 2011, in which his character is killed.^[53] Bieber performed a medley of "U Smile", "Baby", and "Somebody to Love" and briefly played the drums at the 2010 MTV Video Music Awards on September 12, 2010.^[54] Bieber announced in October 2010 that he would release an acoustic album, called My Worlds Acoustic.^[55] It was released on Black Friday in the United States and featured acoustic versions of songs from his previous albums, and accompanied the release of a completely new song titled "Pray".^[56]

A 3-D part-biopic, part-concert film starring Bieber entitled Justin Bieber: Never Say Never, was released on February 11, 2011, directed by Step Up 3D director Jon Chu. It topped the box office with an estimated gross of $12.4 million on its opening day from 3,105 theaters.^[57] It grossed $30.3 million for the weekend and was narrowly beaten by the romantic comedy Just Go With It, which grossed $31 million.^[58] Never Say Never is said to have exceeded industry expectations, nearly matching the $31.1 million grossed by Miley Cyrus's 2008 3-D concert film, Hannah Montana & Miley Cyrus: Best of Both Worlds Concert, which holds the record for the top debut for a music-documentary.^[59][60] Never Say Never grossed a total of $98,441,954 worldwide.^[61] The film is accompanied by his second remix album, Never Say Never – The Remixes, released February 14, 2011, and features remixes of songs from his debut album, with guest appearances from Miley Cyrus, Chris Brown, and Kanye West, among others.^[62]

[edit] 2011–present: Under The Mistletoe and Believe

On February 27, 2011, Bieber attended the 2011 Vanity Fair Oscar Party with American actress and singer Selena Gomez,^[63] confirming several months of media speculation about a romantic relationship between the pair.^{[64][65][66][67][68][69]}

In June 2011, Bieber was ranked number 2 on the Forbes list of Best-Paid Celebrities under 30. He is the youngest star and 1 of 7 musicians on the list raking in with $53 million earned in a 12 month period.^[70] On November 1, 2011, Bieber released Under the Mistletoe, his second studio album.^[71] It debuted at number one on the Billboard 200, selling 210,000 copies in its first week of release.^[72]

In late 2011, Bieber began recording his third studio album, entitled Believe. Kanye West and Drake are confirmed to be featured on the album.^[73] On February 22, 2012, Bieber announced via Twitter that the first single off Believe will be released in March 2012.^[74] The following week, Bieber appeared on The Ellen DeGeneres Show to announce that the first single will be called "Boyfriend" and was released on March 26, 2012.^[75] The song was co-written by Mike Posner.^[76] The second single, Die In Your Arms, was released on May 29th, 2012. ^[77]

Image[link]

Justin Bieber has a higher score on the Klout online "influence" scale than Barack Obama or The Dalai Lama.^[78] According to Jan Hoffman of The New York Times, part of Bieber's appeal stems from his YouTube channel. Long before he released his EP, My World, in mid-November, the YouTube videos attracted millions of views.^[18] Braun recognized the appeal. Prior to flying him to Atlanta, Braun wanted to "build him up more on YouTube first" and had Bieber record more home videos for the channel. "I said: 'Justin, sing like there’s no one in the room. But let's not use expensive cameras.' We'll give it to kids, let them do the work, so that they feel like it's theirs", recalled Braun.^[18] Bieber continues to upload videos to the same channel and has opened a Twitter account, from which he interacts with fans regularly;^[10] his account was reported in November 2010 to have over 6 million followers.^[79] Since then he has been consistently gaining followers at an average of 24,000 per day.^[80] The accounts also serve marketing purposes; for example, Bieber's music video for "One Time" only began selling quickly after it was uploaded to YouTube.^[81]

Bieber performing "Favorite Girl" in Zurich, Switzerland April 2011.

Usher comments that while he and Bieber were both signed at the same age, "I had the chance to ramp up my success, where this has happened to Bieber abruptly." As a result, Usher, Braun, Bieber's bodyguard Kenny, and other adults surrounding Bieber constantly coach him on handling fame and his public image.^[18] After signing Bieber, Usher appointed one of his former assistants, Ryan Good, to be Bieber's road manager and stylist. Good, once nicknamed Bieber's "swagger coach", created a "streetwise look" for the singer which consisted of baseball caps, hoodies, dog chains and flashy sneakers. Amy Kaufman of The Los Angeles Times comments, "Though a product of a middle-class suburban upbringing in Stratford, Ontario, Bieber's manner of dress and speech ("Wassup man, how you doin'?" or "It's like, you know, whateva' ") suggest he's mimicking his favorite rappers."^[82]

Bieber is often featured in teen magazines such as Tiger Beat,^[18] and has been labeled as a "teen heartthrob".^[83] Bieber has released a collection of nail varnishes to raise awareness for charity.^[84] Wax statues of Bieber are on display at Madame Tussauds wax museums in New York, Amsterdam and London.^[85] His change of hairstyle in 2010, and the consequent alterations to Bieber products, led to it being called 'the most expensive musical haircut of all time;^[86] one company spent $100,000 to fix its dolls for the 2011 Christmas season.^[87]

Bieber has been criticized for looking and sounding younger than his age, his teen-pop music, image, and frequent media attention.^[88] He has been a frequent target of Internet bloggers and message board posters, notably by users of Internet message board 4chan and users of YouTube.^[89] Nick Collins of The Daily Telegraph speculated that "Bieber's character also appears to strike a particularly sour note with his Internet critics, with many remarks commenting on his youthful appearance, his teen-pop songs, his image as a heart-throb to young teenage girls and his manner of speech".^[90]

Personal views and life[link]

Bieber is a Christian,^[91] and said he has a relationship with Jesus, talks to him and that "he's the reason I'm here".^[92]

Bieber's comments in a February 2011 profile in Rolling Stone sparked controversy.^[93] Asked about abstinence, Bieber responded, "I don't think you should have sex with anyone unless you love them." He said he does not "believe in abortion" and that it is "like killing a baby".^[94] He described sexual orientation as "everyone's own decision."^[95] Bieber has contributed to the It Gets Better Project,^[96] which aims to prevent suicide among LGBT youth.^[97]

Bieber has said he is not interested in obtaining United States citizenship and has criticized America's health care system. Praising Canada as being "the best country in the world", he cited its health care system as a model example.^[94]

In May 2012, Bieber purchased a 10,000 square-foot mansion on 1.3 acres of land, located in the community of Calabasas, California, a suburb of Los Angeles.^[98]

Twitter[link]

As of April 2012^[update], Bieber's Twitter account (@justinbieber) is the second most popular celebrity account behind that of Lady Gaga.^[99] By mid-April 2012, he had over 20 million followers.^[100][101] His follower acquisition is one new follower every other second.^[102][103] His popularity on Twitter at one point accounted for three percent of all Twitter related traffic, with a Twitter employee commenting that "racks of servers are dedicated" to Bieber.^{[103][104][105][106][107][108][109][110][111][112]} This resulted in over 180 million page views for the service each month.^[105] Bieber was frequently a trending topic on Twitter when the feature first launched^[105] because his fans frequently discussed him on the network. ^[113] and was named the top trending star on Twitter in 2010;^[114] Klout gave his account a score of 100.^[115][116]

The size of Bieber's and Gaga's follower bases are cited as a reason why marketers should pay attention to Twitter:^[117] with an ability to reach millions of people with a single tweet.^[117] 8.3% of tweets mentioning "bieber" were semi-automated and probably Twitter related spam.^[118] Research done about Twitter and the 2011 Egyptian revolution includes Bieber as he made tweets about the topic at a time when he had roughly 8 million followers. His multiple tweets resulted in 32,000 responses each, which made Bieber's Twitter account one of the single largest nodes for discussion about the uprising one of the largest on Twitter.^[119][120]

In March 2012, Bieber fans launched an unsuccessful attempt to unseat Lady Gaga as the most popular celebrity on Twitter. Neither Bieber nor Lady Gaga discussed their mutual fanbase's campaigns on Twitter.^[121]

Discography[link]

Justin Bieber portal

• My World 2.0 (2010)
• Under the Mistletoe (2011)
• Believe (2012)

Tours[link]

• 2009: Urban Behavior Tour
• 2010–2011: My World Tour
• 2012-2013: Believe Tour

Filmography[link]

Awards and nominations[link]

References[link]