Researchers Find Super-Social Gene May Hold Clues to Autism and Other Disorders

SAN DIEGO -- If they had their way, Tristan and Tyler Waldner would be friends with everybody.
The 7-year-old twins from San Diego, Calif., have Williams Syndrome, a rare genetic disorder that makes them unusually social, so outgoing and gregarious that, to them, there's no such thing as a stranger.
At the library, on the playground, and even with surprise guests at dinner, the blond boys are charming and chatty, brimming with questions — “Where do you live? Did you drive here or fly here? Do you have kids?” — but with none of the shyness or social reserve you’d expect from typical second-graders.