Reality TV stars are often criticised for becoming famous as a result of being distinctly ordinary.
But America's latest reality duo are far from average.
The first amazing thing conjoined twins Abigail and Brittany Hensel did was to survive after doctors told their parents they wouldn't last more than a few hours after being born.
Now 22-years-old the twins have not only proved doctors wrong they have astonished them with their development into darling children, typical teenagers and, lately, beautiful young adults.
Their new reality show Abby and Brittany chronicles the next part of their journey as the girls take the leap from students to young professionals via a summer travelling through Europe with their friends.
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TLC's Abby and Brittany show will chart the next chapter of the twins life as they graduate from college and travel across Europe with their friends
Astonishing development: The 22-year-olds, who share one body, have amazed doctors who thought they wouldn't survive the night as newborns
The girls are shown graduating from Bethel University in Minnesota in the first episode of the show
In the first episode of the show the twins, who share one body fused at the torso, are shown celebrating their 22nd birthday, graduating from Bethel University in Minnesota and getting ready for job interviews.
The girls first captivated the world in 1996 when they appeared on The Oprah Winfrey Show and the cover of Life Magazine.
Since then they have lived a quiet, normal life with their family in Minnesota, keeping away from the media spotlight until they agreed to appear on a documentary for TLC when they turned 16.
One in a trillion: The Hensels are believed to be one of only a few sets of dicephalus twins in history to survive infancy
Extraordinary bond: Conjoined twins Abigail and Brittany Hensel have been given their own reality TV show charting their graduation and travels through Europe
The broadcaster has now given them their own show called 'Abby and Brittany' which will premiere on August 28.
When the Hensel twins were born on March 7, 1990, in Minnesota in the United States, doctors warned their parents Patty, a registered nurse, and Mike, a carpenter and landscaper, that they were unlikely to survive the night.
But that prediction was to prove wildy wrong.
When growing up, they, like many twins, had very different personalities and tastes.
Abigail, the feisty, stubborn one, liked orange juice for breakfast, while Brittany, the joker of the family, would only touch milk.
Feat of teamwork: The girls passed their driving test on their 16th birthday, with each twin using one arm to control the steering wheel
Remarkable: The girls have two spines, two hearts, two oesophagi, two stomachs, three kidneys, two gall bladders, four lungs, one liver, one ribcage, a shared circulatory system and partially shared nervous systems
They also stunned doctors with their astonishing co-ordination while playing the piano, with Abigail taking the right-hand parts and Brittany the left.
They enjoyed sports such as bowling, volleyball, cycling, softball and swimming.
And on their 16th birthday they passed their driving test, a mind-boggling feat of teamwork with each twin using one arm to control the steering wheel.
Speaking at the time, their mother Patty, a registered nurse, conceded that could have been a problem.
'I don't know what would happen if they got pulled over for speeding. Would they each get a ticket or just Abby because it's her foot on the accelerator?'
Much-loved: The girls attended a private church school and are popular with their friends, who treat them no differently from anyone else
The Hensels are believed to be one of only a few sets of dicephalus twins in history to survive infancy, and when they turned 16, they allowed the cameras into their fiercely guarded private world to share this milestone in their lives.
Speaking back then, Brittany said: 'Believe me, we are totally different people.'
It has not been unknown, however, for the twins to go out in a specially made top with two different necklines - to reflect their unique tastes - and leggings with each leg a contrasting colour and a different shoe on each foot.
Just one set of twins in every 40,000 is born connected in some way to each other and only 1 per cent of those survive beyond the first year.
Unique parenting skills: Their mother Patty has encouraged the girls to develop their own individuality and to ensure that if one of the twins misbehaves, she is careful to only scold the one responsible
In unison: The twins display an astonishing sense of co-ordination, with each using one arm to perform tasks, including playing the piano and sport
HENSEL GIRLS ARE RAREST FORM OF CONJOINED TWINS
Yet Patty, 46 and Mike, 47, never once considered having the twins separated, through fear that one or both might die or be left with such severe disabilities their quality of life would be compromised and could no longer enjoy all the activities they love.
They would each have just one arm and one leg and be confined to a wheelchair.
Patty had no idea she was carrying twins until the birth at the local hospital where she worked
'The paediatrician said my babies were together but they had two heads,' she recalled in 2006. 'It was blunt, but completely accurate.
'From the first time we saw them, we thought they were beautiful.
'I kissed Abigail and then Brittany and gave them a hug. It's like that every time I pick them up from school, two kisses and one hug for the most beautiful children in the world.'
Both Mike and Patty's families have lived in a small midwestern farming community of 300 people for generations and it is here where they have brought up the twins and younger brother Dakota, 20, and sister Morgan, 18, away from the media spotlight.
Although Brittany is more susceptible to colds and has twice suffered pneumonia, the twins have remained in good health despite a series of operations.
In infancy, a third undeveloped arm was removed from their chest and aged 12 they underwent surgery to correct scoliosis - curvature of the spine - and expand their chest cavity to prevent future breathing difficulties.
They attended a private church school and are popular with their friends, who treat them no differently from anyone else. Only when the family ventures outside this close-knit community does the curiosity of strangers have the potential to wound.
Once Patty heard a child at a swimming pool ask his mother if she had seen the little girl with two heads. 'We have talked about that with Abigail and Brittany,' she said.
'When children ask the girls if they have two heads, they say they don't but that each has their own head. That's what we have encouraged them to do, to develop their own individuality as much as possible.'
That has meant buying two seats every time they go to the cinema - even though only one will be used - separate meals and two different birthday cakes with candles each year. If one of the twins misbehaves, Patty and Mike are careful to scold the individual responsible - even if the other has been dragged unavoidably into the misdeed.
Yet, while the twins have developed their own tastes in food, drink, clothes and separate personalities, their body works as one - although they have different urges to eat and sleep.
When they eat, they have separate plates. One of them holds the fork and the other the knife to cut the food, and then take turns to put the meal in each other's mouth.
Give and take: What is perhaps most touching about Abigail and Brittany has been their ability to get on, despite their different personalities
What is perhaps most touching about Abigail and Brittany, however, is their ability to get on - despite their different personalities. They seldom argue, despite Abigail always wanting to be the leader and - according to their mother - liking 'to rule the whole house'.
One twin will scratch an itch the other cannot reach or hold her hand still so the other can count during a maths lesson and when Brittany was ill with pneumonia and couldn't keep the medicine down, Abigail volunteered to take it in the hope of making her twin better.
Only once have the twins talked about separation - in childhood - when Abigail became bored and restless after Brittany fell ill with pneumonia and was confined to bed.
She started to suggest being separated from her sister, but when Brittany began to cry Abigail reassured her that everything was fine and that they'd never be parted.
Despite their optimism, devotion to each other and apparent happiness, what of the inevitable challenges they will face in life? It is not clear if either has yet, but will they fall in love and with whom?
Three years ago, unconfirmed reports claimed Brittany was engaged, but no details were given about the fiance.
What if one of the twins detests the boy the other one likes? Will they have children - a choice they must both make in tandem because they share one reproductive system?
There is no medical reason why they shouldn't be able to have children and they have in the past said they would like to start a family.
Their father Mike certainly believes the girls will at the very least get married one day.
Videos: Abby and Brittany aged 16 and 19
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