Even for Darold Treffert, an expert in the study of savants who has met around 300 people with conditions such as autism who possess extraordinary mental abilities, Kim Peek stood out from the pack. Treffert first spoke with Peek on the phone in the 1980s. Peek asked Treffert for his date of birth and then proceeded to recount historical events that had taken place on that day and during that week, Treffert says. This display of recall left Treffert with no doubt that Peek was a savant.

Peek’s abilities dazzled screenwriter Barry Morrow when the two men met in 1984 at a committee meeting of the Association for Retarded Citizens. Morrow went on to pen the script for the 1988 film Rain Man, basing Dustin Hoffman’s character on Peek. 

The concept of savant syndrome dates back to 1887, when physician J. Langdon Down coined the term “idiot savant” for persons who showed low IQ but superlative artistic, musical, mathematical, or other skills. (At the time, the word “idiot” denoted low IQ and was not considered insulting.)