55 Fun Facts About Twins

Which term describes identical twins, as opposed to fraternal ones?

Monozygotic twins are the identical kind: one zygote (from Greek zygotos, 'yoked') splits into two embryos, while dizygotic twins each grow from a separate fertilized egg.

Worldwide, roughly one delivery in how many produces twins?

About 1 in 90: a 2021 global study put twinning at 12 per 1,000 deliveries, while identical twins are rarer at roughly 3 to 4 per 1,000.

Roughly how many twin sets per 1,000 births occur among West Africa's Yoruba people?

About 45 twin sets per 1,000 births, roughly 90 twins per 1,000 babies, several times the global average of about 12 sets per 1,000.

A 2011 global study found the highest national twinning rate, 27.9 per 1,000 births, in which country?

Benin topped the 2011 Smits and Monden survey at 27.9 twin deliveries per 1,000; the lowest rates, under 9 per 1,000, were in South and Southeast Asia and Latin America.

Igbo-Ora, nicknamed the 'Twin Capital of the World,' is a town in which country?

Igbo-Ora sits in Nigeria's Oyo State; locals credit the local diet, though researchers have found no proven cause for its twinning rate.

In Yoruba tradition, if the first-born twin is Taiwo, what is the second-born called?

Kehinde, 'the one who came last', is considered the elder, having sent Taiwo out first to check whether the world was fit to enter.

Which Rio Grande do Sul town is nicknamed 'Land of Twins' for its twinning rate?

A theory blaming Nazi doctor Josef Mengele made headlines, but geneticists point to a founder effect among the town's German and Polish settlers, and the twin births predate his arrival.

Do identical twins have identical fingerprints?

Fingerprints are shaped partly by contact with the womb, so each twin touches a different environment and grows unique ridges. Their DNA is nearly identical, though.

Fraternal twins run in families because some women inherit a tendency to do what?

This tendency to hyper-ovulate is genetically linked, which is why fraternal twins cluster in families. Identical twinning, by contrast, has no known genetic link.

By 2011, roughly what share of US twin births were estimated to result from IVF and similar technology?

About 36 percent: fertility drugs and IVF often produce more than one embryo, which is a big reason twin births climbed so steeply from the 1980s onward.

Researchers suspect as many as how many pregnancies begin as multiples but end with a single baby?

Perhaps 1 in 8: in most cases the lost twin is reabsorbed so early that the mother never knew there were two, which is why early ultrasounds keep turning them up.

Fraternal twins with two different biological fathers are the result of a phenomenon with what name?

Heteropaternal superfecundation happens when two eggs released in the same cycle are fertilized by different men; one study of disputed-paternity twin cases found it about 2.4 percent of the time.

Possibly the longest gap between twin births, 97 days, was recorded in which German city?

Cologne's twins arrived in November 2018 and February 2019; delayed-interval delivery keeps the second twin in the womb after the first comes prematurely, so some twins get different birthdays, months or years.

A private language developed by twins that only the two of them understand is called what?

Cryptophasia comes from the Greek for 'secret speech'; it usually fades as the children learn the language everyone else speaks.

Roughly how often do conjoined twins occur?

About 1 in 50,000 pregnancies; most conjoined twins are girls, by a ratio of about three to one, and the most common type is joined at the chest.

As of 2019, how many cases of semi-identical 'sesquizygotic' twins had been documented?

Only two: the second case, in Brisbane in 2019, showed the twins shared 100 percent of maternal and about 78 percent of paternal DNA, the result of one egg fertilized by two sperm.

Chang and Eng Bunker, the original 'Siamese twins', were born in Siam, now called what?

Siam became Thailand in 1939; the brothers settled in North Carolina, married two sisters, and fathered 21 children between them, none of them conjoined.

Chang and Eng Bunker married Adelaide and Sarah, two sisters with which surname?

The Yates sisters married the twins in a double wedding in 1843; the couples eventually kept two separate households, alternating three days at each.

According to legend, the twin founders of Rome were suckled as infants by which animal?

A she-wolf nursed Romulus and Remus in the cave called the Lupercal; Roman tradition put the city's founding at around 753 BC.

Which pair of mythological twins was placed in the sky as the constellation Gemini?

In the myth only Pollux, son of Zeus, was immortal; when mortal Castor died, Pollux asked to share his immortality and the two became stars.

Who was the famous sister of the Gemini twins of Greek myth?

Helen of Troy was Leda's daughter alongside the twins, who were known collectively as the Dioscuri, 'sons of Zeus', and served as patrons of sailors.

Gemini, the zodiac sign of the twins, is ruled by which planet?

Mercury rules Gemini, the third sign of the zodiac and an air sign; NASA borrowed the name for its two-astronaut spacecraft program in the 1960s.

In the Book of Genesis, the twin Esau sold his birthright to his brother Jacob in exchange for what?

A bowl of red lentil stew, the 'mess of pottage'; Jacob later disguised himself in Esau's clothes to claim their blind father Isaac's blessing as well.

What name was given to Elvis Presley's stillborn twin brother, delivered 35 minutes before him?

Jesse Garon's name rhymed with Elvis's own middle name, Aron; Elvis was raised as an only child in Tupelo, Mississippi, and later Memphis.

Which actor played both Kray twins in the 2015 film Legend?

Tom Hardy played Ronnie and Reggie; the Krays ran the East End 'Firm', owned the nightclub Esmeralda's Barn, and were photographed by David Bailey before being jailed for life in 1969.

Mary-Kate and Ashley Olsen got their start sharing the role of Michelle Tanner on which sitcom?

Full House ran from 1987 to 1995; despite looking alike, the Olsens are fraternal twins, and they founded the luxury fashion label The Row in 2006.

What was the 1990s sitcom starring Tia and Tamera Mowry as twins separated at birth?

Sister, Sister was cancelled by ABC after two seasons and picked up by The WB for four more; both sisters were born in Gelnhausen, West Germany.

In which sport did the Winklevoss twins compete for the US at the 2008 Beijing Olympics?

Rowing: they finished sixth in the men's coxless pair; Armie Hammer played both brothers in The Social Network, and they later founded the crypto exchange Gemini.

In which 1999 Adam Sandler comedy did twins Dylan and Cole Sprouse share the role of a five-year-old?

Big Daddy cast the Arezzo-born brothers as Julian; Cole later played Jughead Jones on Riverdale while Dylan opened a meadery in Brooklyn.

Twins James and Oliver Phelps played which prankster brothers in the Harry Potter films?

They had no acting experience and skipped school to attend an open audition in Leeds. Oliver is the elder by 13 minutes.

What is the name of Scarlett Johansson's twin brother?

Hunter Johansson, her fraternal twin, appeared with her in the 1996 film Manny & Lo and later worked in politics and nonprofits.

Which Oscar-winning actor has an identical twin brother named Sami who is four minutes younger?

Rami Malek and Sami were both in their high school drama department; only Rami went on to play Freddie Mercury in Bohemian Rhapsody.

Supermodel Gisele Bundchen's fraternal twin sister Patricia took over which job for her in 2021?

Patricia became her manager in 2021 when Gisele left IMG Models after 22 years; Gisele grew up with five sisters in Brazil.

George W. Bush's twin daughters Jenna and Barbara were born in 1981 in which Texas city?

They were born at Dallas's Baylor University Medical Center; Jenna went on to co-host the fourth hour of NBC's Today, and the twins co-wrote the memoir Sisters First.

How many big-league home runs did Jose Canseco's twin Ozzie hit?

Zero: Ozzie played just 24 MLB games without a homer, though he smashed 48 in one Atlantic League season for the Newark Bears in 2000.

Identical twins Daniel and Henrik Sedin spent their entire NHL careers with which team?

They were drafted second and third overall in 1999 and entered the Hockey Hall of Fame together in 2022; Henrik was born six minutes before Daniel.

Tiki Barber's twin Ronde won a Super Bowl as a cornerback for which team?

Both played college ball at Virginia. Ronde, seven minutes younger, was elected to the Pro Football Hall of Fame in 2023, and the pair have co-written children's books.

In the 1988 comedy Twins, what made Schwarzenegger's and DeVito's characters twins?

A secret genetic experiment produced them; the stars and director Ivan Reitman skipped their salaries for a share of the profits, and the film grossed $216 million on an $18 million budget.

Lindsay Lohan made her film debut playing both twins in the 1998 remake of which Disney film?

In The Parent Trap, twins Hallie and Annie meet at summer camp and scheme to reunite their parents; the story comes from Erich Kästner's 1949 novel Das doppelte Lottchen.

The Grady girls in The Shining were played by real identical twins with what surname?

Lisa and Louise Burns played the pair. Oddly, dialogue in the film says the sisters were 'about eight and ten,' so they weren't strictly twins in the story.

In which month is the Twins Days festival held in Twinsburg, Ohio?

The festival began in 1976 and draws thousands of twin sets each first full weekend of August. Scientists show up too, recruiting pairs for genetics studies.

Minnesota's 'Twin Cities' are Minneapolis and which neighbor to its east?

Saint Paul is the state capital while Minneapolis is the larger city, which is why the state's pro sports teams mostly use 'Minnesota' rather than either name.

Which detail about the 'Jim twins', separated at birth and reunited at 39, was actually true?

They also both owned dogs named Toy and gave their first sons nearly identical names. Their case launched the Minnesota Study of Twins Reared Apart in 1979.

Scott Kelly's identical twin, his Earth control in NASA's Twins Study, became a US senator for which state?

Mark Kelly won Arizona's 2020 special Senate election; a former astronaut married to former congresswoman Gabby Giffords, he was the control while the study tracked Scott's gene expression and telomeres.

What do the names of Kin Narita and Gin Kanie, Japan's celebrity centenarian twins, mean?

Kin means gold and Gin silver; Kin died at 107 in 2000 and Gin at 108 in 2001, after a decade of television fame that began with their 100th birthdays.

How many pairs of twins did the wife of Feodor Vassilyev, record-holder for most children, reportedly have?

Sixteen pairs of twins: her tally of 69 also included seven sets of triplets and four sets of quadruplets, and reportedly no single births at all.

What type of conjoined twins are Abby and Brittany Hensel?

Dicephalic parapagus twins share one torso with two heads; the Hensels were born in Carver County, Minnesota, while thoracopagus, joined at the chest, is the most common type.

By what percentage did the US twin birth rate rise between 1980 and 2009?

A 76 percent rise: the CDC counted 18.9 twins per 1,000 births in 1980 and 33.2 in 2009, driven by fertility treatment and women starting families later.

A specific type of which food, rich in a natural phytoestrogen, may explain the Yoruba's high twinning rate?

A local variety of yam is the suspect; its phytoestrogen is thought to stimulate the ovaries into releasing an egg from each side.

Per a 2006 study, how did vegan mothers' odds of having twins compare with omnivores'?

Vegans had about one-fifth the twinning rate; Gary Steinman pointed to insulin-like growth factor in dairy products as a possible stimulant of multiple ovulation.

Twin-to-twin transfusion syndrome can only affect twins that share what?

Sharing a placenta is the precondition: vessel connections across it let one twin pump blood to the other, and laser ablation of those vessels is the main treatment.

What was Lydia Fairchild, whom DNA tests wrongly said was not her children's mother?

She was a chimera: two of her children came from eggs derived from cells of her own absorbed twin, a condition that can also produce patchy skin colouring.

Which animal routinely gives birth to identical quadruplets from a single egg?

The nine-banded armadillo splits one fertilized egg into four genetically identical pups, a consequence of a uterus that offers just one implantation site.

The first DNA-confirmed identical twins in dogs were born by C-section in 2016 to which breed?

The Irish Wolfhound puppies shared a single placenta; vet Kurt de Cramer delivered them by C-section in South Africa and genetic tests confirmed them as identical.

Monoamniotic twins, sharing one sac, result when a single embryo divides after how long?

Splitting after the first week, around days 8 to 13, leaves one sac and one placenta; twins that split within about three days get separate placentas, like fraternal twins.