The series exploring remarkable tales of human experience continues this week with the story of Flo and Kay, the world’s only female autistic savant twins. Savantism is a rare condition in which sufferers of developmental disorders, often autism, are capable of acts of genius that far outstrip their expected levels of ability. In Flo and Kay’s case, they each have extraordinary memories for facts and dates. Through interviews with several medical professionals, Extraordinary People: The Rainman Twins attempts to expose the truth behind this oft-misunderstood condition. Describing themselves as “human computers”, Flo and Kay can access their memories and make calculations more efficiently than most people.

Among their many special talents is an ability to compute the day of the week for any date – past or future. For any given day of their lives, they can remember what the weather was like and even what they had for breakfast. According to psychologist Dr David Holmes, Flo and Kay’s wellordered minds are also reflected in their wellordered lives. “The more that they can create order, the more secure they feel,” he says.

An example of how this desire for order has manifested itself in the twins is their obsession with routinely watching television. In particular, they are big fans of Dick Clark. The popular US television personality is an all-American institution, and appears on Flo and Kay’s favourite show, ‘$100,000 Pyramid’. They call him their “personal saviour” and religiously watch every episode of the game show. ‘$100,000 Pyramid’ is packed with facts, figures and trivia, and the twins catalogue all the questions and answers featured. They even record the number of times the buzzer sounds in each episode. So when the programme was taken off the air, the sisters were devastated.

“We prayed for it to come on,” says Flo. “And our mother always used to say, ‘Your prayers are always answered.’ But this time it doesn’t work.” Although it is widely assumed that the twins have savantism, it has never been formally diagnosed – and the condition is not an officially recognised medical disorder. The only thing doctors know for sure is that they have autism. But just how autistic are they?

At 52 years of age, the twins are bubbly and sociable. They are passionate about music, enjoy going to gigs and love to laugh. This means that they do not fit the classic stereotype of autism sufferers. At the New Jersey Neuroscience Institute, Dr Nancy Isenberg uses the Autism Diagnostic Observation Schedule (ADOS) to perform her assessment. She asks Flo and Kay a series of questions about friendships and emotions. As well as listening to their answers, she observes the sisters’ body language. Dr Isenberg concludes that despite Flo and Kay’s outgoing natures, they still possess the standard signs of autism – minimal eye contact, poorly modulated voices and failure to engage in conversation.

Next, Dr Darold Treffert is asked to assess Flo and Kay. Dr Treffert is a leading expert on autistic savantism – he was the consultant on the film ‘Rain Man’ and advised Dustin Hoffman on how to portray his character. After a brief meeting with the sisters, there is no doubt in his mind that they are autistic savants. But Dr Treffert is quick to point out that there is still so much to learn about the disorder. “Until we can account for the savant, we can’t account for brain function overall. Until we can explain the savant, we really can’t explain ourselves,” he concludes.