Savantism is a rare condition in which people with developmental delays of the brain (notably autism spectrum), and/or brain injury, demonstrate profound and prodigious capacities and/or abilities far in excess of what would be considered normal.

According to Darold Treffert, the leading researcher in the study of savant syndrome, almost all savants have prodigious memory of a special type, which he describes as "very deep, but exceedingly narrow". It is wide in the sense that they can have an exceptional memory but have a hard time putting it to use. Certain savants have also been shown to display advanced skill in one or more of five major areas: Art, musical abilities, calendar calculating, mathematics and spatial skills. Most savants display social deficiencies, generally consistent with an Autism spectrum disorder, although symptoms can recede over time.^[1] It has been observed that savants lack Theory of Mind.

Savant syndrome is poorly understood. No widely accepted cognitive theory explains savants' combination of talent and deficit.^[2] It has been suggested that individuals with autism are biased towards detail-focused processing and that this cognitive style predisposes both individuals with and without autism to savant talents.^[3] Another hypothesis is that savants hyper-systemize, predisposing them to show talent. Hyper-systemizing is an extreme state in the empathizing–systemizing theory that classifies people based on their skills in empathizing with others versus systemizing facts about the external world.^[4] Also, the attention to detail shown by many savants may be a consequence of enhanced perception or sensory hypersensitivity in individuals with autism.^[4][5] It has also been suggested that savants operate by directly accessing low-level, less-processed information that exists in all human brains but is normally unavailable to conscious awareness.^[6]

• One in ten people with autism has savant skills.^[1]
• 50% of savants have autism; the other 50% often have psychological disorders or mental illnesses.^[1]
• Prodigious savants have very significant disorder and disability. Examples include Richard Wawro, Henriett Seth F., and Jonathan Lerman.

A 2009 British study of 137 parents of autistic children found that 28% believed their offspring met the criteria for a savant skill, defined as a skill or power "at a level that would be unusual even for normal people".^[7]

The term idiot savant (French for "learned idiot" or "knowledgeable idiot") was first used to describe the condition in 1887 by John Langdon Down, who is known for his description of Down Syndrome. The term "idiot savant" was later described as a misnomer because not all reported cases fit the definition of idiot, originally used for a person with a very severe mental retardation. The term autistic savant was also used as a diagnosis for this disorder. Like idiot savant, the term autistic savant also became looked at as a misnomer because only one-half of those who were diagnosed at the time with savant syndrome had autism. Upon realization of the need for accuracy of diagnosis and dignity towards the individual, the term savant syndrome became widely accepted terminology.^[1]

The 1988 fictional film Rain Man was loosely based on the savant Kim Peek among others.^[8]

A prodigious savant is someone with a skill level equivalent to that of a prodigy, regardless of any cognitive disability. The most common trait of prodigious savants is their seemingly limitless mnemonic skills, with many having eidetic or photographic memories. Prodigious savants are extremely rare, with fewer than one hundred noted in more than a century of literature on the subject. Treffert estimates that fewer than fifty or so such individuals are alive today.

The following are well-known people with savant syndrome, noted for their talent in their identified fields:

• Kim Peek, mnemonist, speed reader and calculator, although not autistic^[9]
• Mark Boerebach, Australian internet Disk jockey, subject of the documentary Rainman goes to Rockwiz
• Alonzo Clemons, American clay sculptor^[10]
• Tony DeBlois, blind American musician^[11]
• Leslie Lemke, blind American musician^[12]
• Jonathan Lerman, American artist^[13]
• Thristan Mendoza, Filipino marimba prodigy^[14]
• Gottfried Mind, Swiss artist known as the "Raphael of Cats"
• Derek Paravicini, blind British musician^[15]
• Anthony Torrone, American Christian writer^[16][17]
• Gilles Tréhin, artist, author
• James Henry Pullen, gifted British carpenter^[18]
• Matt Savage, American autistic jazz prodigy^[19][20]
• Henriett Seth F., Hungarian autistic savant, poet, writer, and artist^[21]
• Stephen Wiltshire, British architectural artist^[22][23]
• Richard Wawro, British artist^[12]
• George and Charles Finn, calendar calculator twins^[24][25]
• Florence 'Flo' and Katherine 'Kay' Lyman, calendar calculator twins. Featured in a documentary produced by TV network TLC entitled Twin Savants: Flo & Kay^[26]
• Derek Amato, American pianist and singer.^[27]
• Temple Grandin, Professor of Animal Science at Colorado State University, and consultant to the livestock industry in animal behavior^[28]
• Jason D. Padgett, American Mathematical Artist^[29][30]
• Daniel Tammet, British author.
• Rex Lewis-Clack, blind American pianist.
• Orlando Serrell, sudden savant, calendrical calculation, mnemonist, featured on English version of Expedition ins Gehirn.

• Asperger syndrome
• PPP1R1B (Gene linking genius with insanity)
• Ideasthesia
• Creativity and mental illness

The Wisconsin Medical Society lists 29 savant profiles.