Twin sisters fed up at that their family couldn't understand them began speaking a sped-up version of a Caribbean language and decided then that they wouldn't bother conversing with anyone else.
June and Jennifer Gibbons exclusively spoke to each other for 29 years, and in that time they made a disturbing pact which meant one of them must die for the other to live a normal life.
The duo were inseparable, and became known as the 'silent twins'. Having both developed a speech impediment when they were only children and opting to speak their own version of Bajan Creole, a native spoken language to Barbados.
The Caribbean nation was where their parents originated from before moving to England and later Wales - but it was their closeness which was ultimately their downfall.
Advert
After committing a series of crimes together, from vandalism to theft and even arson, the UK's judicial system saw enough to send the Gibbons twins to Broadmoor Hospital, a high-security mental health unit, at just 19 years old.
But after 11 years the pair were transferred, and complications arose while in transit resulting in Jennifer's untimely death.
During the trip, Jennifer became suddenly unresponsive and passed away due to inflammation of the heart.
Strangely, following her twin's death, June suddenly started speaking and has ever since.
Advert
That was in 1993, and for the last 32 years June has navigated the world alone, with the exception of Marjorie Wallace - an investigative journalist who spent years getting to know the sisters.
Five years into their time at the hospital, Marjorie published a book titled The Silent Twins.
The book has since been converted into a screenplay The Silent Twins - a 2022 thriller/drama starring Letitia Wright.
Advert
Marjorie revealed her belief that the twins had come up with a pact during their time together, saying: "The real story came from their diaries, 3,000 words a day each about each other and their love-hate relationship. Through reading their diaries, I got to know the story of their pact and what was, finally, the tragedy of their lives."
It is of Marjorie's opinion that one of the sister's had to die in order for the other to live a normal life.
Speaking to BBC Radio Wales, she continued: "One of the girls had to die, to sacrifice themselves so the other would be truly liberated, and they decided it would be Jennifer."
Advert
Marjorie claimed June was 'suspended by both grief and liberation'.
"They could not have gone on together. She accepts that with a wonderful sense of resolution, and I find June to be the most wonderful, comforting friend," she said.
Marjorie added: "I have never really left the story, because I met June and Jennifer when they were 18 years old and have remained with them ever since. In a way, their story has been my story, we have had our lives intertwined for 40 years.
"There were times when the visits were quite sad, but most of the time they were really enjoyable because the twins, despite all their complexities, had the most wonderful sense of humour. Still today, June has this infectious laugh."
Joe Yates