Ever since he was small, John Robison had longed to connect with other people, but by the time he was a teenager, his odd habits-an inclination to blurt out non sequiturs, avoid eye contact, dismantle radios, and dig five-foot holes (and stick his younger brother in them)-had earned him the label "social deviant." No guidance came from his mother, who conversed with light fixtures, or his father, who spent evenings pickling himself in sherry. It was...