Savant

Researchers remain uncertain about what causes some developmentally disabled or autistic people to become savants. Some believe that certain savants have eidetic (intensely visual) memories. Their skills are based entirely on their ability to memorize. While this theory can account for some savant skills, it fails to explain others.

Some experts believe that intelligence is not a single quality, but rather that mental ability is separated into multiple intelligences which may be unrelated to one another. If this is true, it could explain how mental retardation or autism and savant skills can coexist in one person. Some experts suspect that developmentally disabled savants have inherited two separate genes, one for mental retardation and one for the special ability; however, only some savants have family histories that contain special skills.

Some researchers have speculated that autistic or developmentally disabled persons may receive only a limited amount of sensory stimulation. This low level of stimulation might be due to biological causes, or could be due to the fact that such people are sometimes ignored by others and live in relative isolation. According to this theory, the resulting boredom could lead to the development of super-intense concentration levels that normal people are unable to achieve. Again, this theory can account for some but not all savants.

Another theory holds that since savants cannot think abstractly, they come to rely entirely on concrete thinking, channeling all of their mental energy into one form of expression, be it art or calendar calculating. Finally, some researchers think that savants may have some brain injury or abnormality on the left side of the brain, the side which controls language, or to other areas of the brain which control abstract thinking. While this may be true for some savants, others show normal electrical activity in the brain when they are tested.