BY age 2 it was clear that the boy had a sensibility all his own, affectionate and distant at the same time, often more focused on patterns and objects than the people around him.
He was neither naturally social like his mother, nor an early and gifted reader like his father. Quirky, curious, exuberant, he would leap up and dance across the floor after solving a problem or winning a game, duck walking like an N.F.L. receiver posing for a highlight film.
Yet after Phil and Susan Schwarz received a diagnosis for their son, Jeremy, of high functioning autism, they began to think carefully about their own behaviors and histories.
Mr. Schwarz, a software developer in Framingham, Mass., found in his son’s diagnosis a new language to understand his own life. His sensitivities when growing up to loud noises and bright light, his own diffidence through school, his parents’ and grandparents’ special intellectual skills — all echoed through his and Jeremy’s behavior, like some ancient rhythm.
His son’s diagnosis, Mr. Schwarz said, “provided a frame in which a whole bunch of seemingly unrelated aspects of my own life growing up fit together for the first time.”