60 Fun Facts About Twins

Twins that develop from a single fertilized egg that splits into two embryos are called what?

Monozygotic twins are the 'identical' kind; dizygotic twins each grow from a separate egg. The Greek roots literally mean 'one yolk' versus 'two yolks.'

Roughly what share of human births are twins?

That works out to about 1.1 percent of births. Identical twins are much rarer, at roughly 3 to 4 per 1,000 births.

The Yoruba people of West Africa have the world's highest twinning rate. Roughly how many twin sets are born per 1,000 live births there?

That is 90 to 100 twins per 1,000 births, several times the global average. Twins hold a special place in Yoruba religion, where they are called Ibeji.

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

The same study found the lowest rates in South and Southeast Asia and Latin America, where twinning runs below 9 per 1,000.

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

Locals often credit the diet, and researchers have looked at a chemical found in yam peelings, though nothing has been proven.

In Yoruba tradition, the first-born twin is named Taiwo. What is the second-born twin called?

Yoruba belief flips the usual order: the second-born is considered the elder, having sent the first out 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.

'Mirror image' twins, with reversed features, result when the egg splits at what point?

The later-than-usual split can leave one twin right-handed and the other left-handed, with hair whorls and even birthmarks on opposite sides.

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.

Compared with younger mothers, the rate of fraternal twins roughly doubles for mothers over what age?

Rising maternal age and fertility treatments together drove a 52 percent jump in U.S. twin births between 1980 and 1997.

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

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?

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?

It happens when two eggs released in the same cycle are fertilized by different men. Among disputed-paternity twin cases in one study, it turned up about 2.4 percent of the time.

How rare is superfetation, conceiving again while already pregnant, in humans?

The result is 'twins' of different gestational ages in the same womb. It's much more common in animals such as hares and badgers.

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

Delayed-interval delivery can let doctors keep the second twin in the womb after the first arrives prematurely, so some twins end up with different birthdays, months, or even years.

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

The name comes from Greek for 'secret speech.' It usually fades as the children learn the language everyone else speaks.

Roughly how often do conjoined twins occur?

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?

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 being fertilized by two sperm.

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

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 double wedding took place in 1843, and the twins 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?

The cave where it supposedly happened is 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.

The Gemini twins of Greek myth had a famous sister. Who was she?

All three were children of Leda; the twins 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?

Gemini is 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?

Esau was the firstborn; 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?

The name rhymed with Elvis's own middle name, Aron. Elvis was raised as an only child in Tupelo, Mississippi.

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

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?

Despite looking alike, the Olsens are fraternal twins. They went on to found the luxury fashion label The Row in 2006.

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

ABC cancelled it after two seasons and The WB picked it up 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?

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?

The brothers were born in Arezzo, Italy. 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.

Scarlett Johansson has a twin. What is her brother's name?

Rami Malek, Ashton Kutcher, Gisele Bundchen, and Kiefer Sutherland are also twins, which makes 'famous twins' a surprisingly long list.

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

Both brothers were in their high school drama department; only one went on to play Freddie Mercury.

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

Gisele grew up with five sisters in Brazil, and left IMG Models after 22 years to have her twin run her career.

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

Jenna went on to co-host the fourth hour of NBC's Today, and the twins co-wrote the memoir Sisters First; Jenna was named after her maternal grandmother.

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

Ozzie played just 24 MLB games, though he did smash 48 homers in one Atlantic League season for the Newark Bears in 2000.

Doubles greats Bob and Mike Bryan are 'mirror twins'. What does that mean on court?

The Bryans won 16 Grand Slam men's doubles titles together and 2012 Olympic gold, celebrating points with their signature chest bump.

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?

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?

Twins Hallie and Annie meet at summer camp and scheme to reunite their parents. The story comes from Erich Kastner's 1949 German 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.

What did Twinsburg, Ohio do in 1818 to earn land and school money from twins Moses and Aaron Wilcox?

The town obliged. The Wilcox twins reportedly married sisters, shared business interests, and died within hours of each other.

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 is also a former astronaut and is married to former congresswoman Gabby Giffords. The study found changes in Scott's gene expression and telomere length.

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

Kin died at 107 and Gin at 108. Their favorite food, they said, was red-fleshed fish.

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

Her tally of 69 children 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, who share one body with two heads?

They were born in Carver County, Minnesota. Thoracopagus, joined at the chest, is the most common type, making up about 28 percent of cases.

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

The rate went from 9.4 to 16.7 twin sets per 1,000 births, 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?

The compound 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'?

The researchers pointed to insulin-like growth factor in dairy products as a possible stimulant of multiple ovulation.

Twin pregnancies last about how many weeks on average, three weeks short of full term?

More than half of twins weigh under 5.5 pounds at birth, largely because they tend to arrive early.

DNA tests wrongly said Lydia Fairchild was not the mother of her own children. What was she?

Two of her children came from eggs derived from cells of her own absorbed twin, a condition that can produce patchy skin colouring.

Which animal routinely produces identical twins, sometimes two sets in one reproductive cycle?

Scientists think the habit evolved to prevent inbreeding by pushing offspring out of the nest to find unrelated mates.

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

The puppies shared a single placenta and were studied by South African scientists.

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

Twins that split within four days get separate placentas, making them indistinguishable in the womb from fraternal twins.