There’s a scene in the 1988 movie Rain Man in which Raymond Babbitt (played by Dustin Hoffman) recites a waitress’s phone number. Naturally the waitress is shocked. Instead of mental telepathy, Raymond had memorized the entire telephone book and instantly recognized the name on her nametag. Hoffman’s character was heavily influenced by the life of Kim Peek, a real memory savant who recently passed away. Peek was born without a corpus callosum, the fibers that connect the right and left hemispheres of the brain. He was also born missing parts of the cerebellum, which is important for motor control and the learning of complex, well-rehearsed routines. But what Peek lacked in brain connections and conceptual cognitive functioning, he more than made up for in memory. He had the extraordinary ability to memorize any text in just one sitting. With two pages in front of him, he had the uncanny ability for each eye to focus on a different page. His repertoire included the Bible, the complete works of Shakespeare, U.S. area codes and zip codes, and roughly 12,000 other books. He was known to stop performances to correct actors and musicians who had made a mistake! He could also tell you what day of the week your birthday fell on in any year.
Savantism disproportionately affects males, with about five male savants for every one female, and the syndrome generally occurs in people with IQs between 40 and 70. Like others with ASD, when savants take IQ tests they tend to score higher on nonverbal problems than verbal problems. As Darold Treffert, a world-renowned expert on savant syndrome, observes, “IQ scores, in my experience with savants, fail to adequately capture and reflect the many separate elements and abilities that contribute to ‘intelligence’ overall in everyone.”
Even so, savants vary markedly in their abilities. Savant skills fall along a continuum, ranging from “splinter skills” (such as memorization of license plates), to “talented” savants who have musical or artistic skills that exceed what is expected based on their handicap, to “prodigious” savants where the skill is so remarkable it would be impressive with or without the disability. To date, fewer than 100 prodigious savants have been documented. Interestingly, there is almost always no “dreaded trade-off ” between the incredible skills of savants and their development of language, social skills, and daily living functioning.