PERIODICALS

tarded, often autistic; six out of seven are males. Most excel at "right-brained" activi- ties, such as music and art. Other savants are "left-brained" mathematical wizards or "lightning calculators" who can, for exam- ple, instantly determine whether Christ- mas fell on a Sunday in 1654.
Researchers for more than a century have sought the causes of this rare endow- ment of gift and affliction-without great success. Recently, says Treffert, Harvard n...