Savant syndrome, is not a recognized medical diagnosis, but researcher Darold Treffer describes it as a rare condition in which persons with developmental disorders (including autism spectrum disorders) have one or more areas of expertise, ability or brilliance that are in contrast with the individual's overall limitations. Treffert says the condition can be genetic, but can also be acquired. by Peter Voyiatzakis.

According to Treffert, about half of the people with savant syndrome have autistic disorder, while the other half have another developmental disability, mental retardation, brain injury or disease. He says, "... not all autistic persons have savant syndrome and not all persons with savant syndrome have autistic disorder". Other researchers state that autistic traits and savant skills may be linked, or have challenged some earlier conclusions about savant syndrome as "hearsay, uncorroborated by independent scrutiny".

According to Treffert, something that almost all savants have in common is a prodigious memory of a special type, a memory that he describes as "very deep, but exceedingly narrow". Narrow in the sense that they can recall but have a hard time putting it to use.

Savant-like skills may exist in everyone and have been simulated by directing low-frequency magnetic pulses into the brain's left fronto- temporal lobe, which is thought to activate the region and allow for more-direct processing of a savant- like task involving rapid counting.

Impressive mathematical abilities that savants possess often include lightening calculation. Calendar memory is sometimes seen, if the savant is asked a question of the type “What day of the week was January 14 th 1973?”. A savant can give the answer within seconds. At the 1964 in the Annual Meeting of American Psychiatric Association, two autistic identical twin brothers were presented who had a calendar calculating span of over years backwards and forwards.

Others can multiply and divide huge numbers and calculate square roots in their heads, yet often have difficulty with simple arithmetic and are unable to accomplish simple mathematical transactions in daily life, like counting out change in a shop.