5. The Gibbons Sisters
Dubbed the Silent Twins because they only communicated with their immediate family, June and Jennifer Gibbons were born in Wales in 1963 and grew up as social pariahs who were frequently bullied. They had speech impediments, and as the years went by, their secret twin language became more unique and less intelligible to outsiders. The sisters, who committed several crimes, including arson and petty theft, were committed to England's Broadmoor Hospital, where they lived for 11 years and were later diagnosed with schizophrenia. Both were writers who each published one novel; the Guardian describes June's The Pepsi-Cola Addict as a tale about "a high school hero seduced by his teacher and sent to a cruel reformatory," while Jennifer's Discomania is centered on a local disco that "incites patrons to acts of insane violence." According to Marjorie Wallace's 1986 nonfiction book, The Silent Twins, the sisters had an intense love-hate relationship and eventually made a pact while at Broadmoor: one had to die so the other could lead a normal life. Jennifer even admitted to Wallace during a visit: "I'm going to die. We've decided." In 1993, hours after their release, Jennifer, at the age of 29, died on her sister's shoulder from a sudden inflammation of the heart muscle. The cause remains a mystery.