The family had been living in Europe, where Briant had a promising career in international business and Maria Teresa, the daughter of a Brazilian diplomat, had embraced an expatriate lifestyle. There Justin found some comfort drawing characters from the Disney videos he watched incessantly; at 5, he littered the Canha home with hundreds of likenesses of Dumbo, Simba and a “Jungle Book” favorite, Baloo the Bear.

But when Justin was in first grade, near Munich, his tantrums became so frequent that he was often removed from the classroom. For months, he would eat only grilled cheese sandwiches. A generation earlier, his parents might have placed Justin in an institution. Instead, the Canhas returned to the United States in 1997 to look for better services.

The realization that Justin was among the most severely impaired in the classroom set aside for children with autism in their new Florida school district was a blow to his mother, already battling depression. But with help from a new form of behavioral therapy that would prove to be one of the few effective interventions for some with the condition, Justin’s tantrums subsided.

With positive reinforcements for small tasks, Justin was coaxed by his therapists to answer questions like “what did you do today?” by drawing, providing a first glimpse of the confusion behind his outbursts, as well as his sense of humor.

The day a teacher at school took his markers away, he drew himself crying on a long, winding road home. After his father returned from a fishing trip, Justin drew a “bad dream”: his own body on a plate, a fish above him with knife and fork, ready to dig in. By the time the Canhas moved to be near family in Providence, R.I., Justin, 9, had taken the top award in a cartooning contest for students in kindergarten through 12th grade. His diet, still devoid of all vegetables, had expanded. He spoke a few short phrases.

And by the time Briant was offered a job in northern New Jersey a year later, Maria Teresa had learned of “inclusion,” a practice that allowed students with disabilities to participate fully in mainstream classes. Said to produce better academic outcomes for such students and instill compassion in their classmates, it held the chance for Justin, his mother believed, to learn the social language that was still so foreign to him.

It took a year to find a public school that would take Justin on those terms; over the 1990s, federal courts had ruled that districts must try to integrate students with disabilities, but gave them discretion. Three superintendents told his mother without even meeting Justin that they would bus him to a specialized private school.