The history of science is studded with stories of simultaneous discovery, in which two imaginative souls (or more!) turn out to have been digging tunnels to the same unspoiled destination. The most fabled example is calculus, developed independently in two different countries by Isaac Newton and Gottfried Wilhelm von Leibniz, but the list stretches back centuries and unfurls right into the present. One can add to it sunspots, evolution, platinum, chloroform . . . and now autism, as the science journalist Steve Silberman informs us, identified separately by Leo Kanner and Hans Asperger. The crucial difference is that Kanner had the fortune to publish his work in Baltimore, while Asperger had the misfortune to publish his in Nazi-controlled Vienna, and this accident of geopolitics lies at the tragic core of Silberman’s ambitious, meticulous and largehearted (if occasionally long-winded) history, “NeuroTribes: The Legacy of Autism and the Future of ­Neurodiversity.”

Over his many years at the Children’s Clinic in Vienna, Hans Asperger studied more than 200 children he would ultimately treat for what he called autistische Psychopathen (autistic psychopathy). Some were prodigies who couldn’t make it through school; others were more disabled and were shunted into asylums. But what they all had in common was a family of symptoms — in Silberman’s words, “social awkwardness, precocious abilities, and fascination with rules, laws, and schedules” — that Asperger recognized, right away, made up a continuum, one occupied by children and adults alike, and he viewed those differences as cause for celebration, not distress. When he finally shared his findings with the world, the only reason he focused on his higher-­functioning patients, Silberman contends, was a chilling function of the era: The ­Nazis, on a mad campaign to purge the land of the “feebleminded,” were euthanizing institutionalized children with abandon. In so doing, Asper­ger accidentally gave the impression that autism was a rarefied condition among young gen­iuses, not the common syndrome he knew it to be. His paper on the subject, published in 1944, remained unavailable in English for decades, and his records were “buried with the ashes of his clinic,” which was bombed the same year.

Meanwhile, in the United States, a brilliant, energetic child psychiatrist named Leo Kanner was developing a radically different picture of autism, one that stipulated the condition was uncommon and unique, affecting only young children (anyone older was schizophrenic, psychotic — anything else) and, though biological in origin, somehow activated by cold and withholding parents. “By blaming parents for inadvertently causing their children’s autism,” Silberman writes, “Kanner made his syndrome a source of shame and stigma for families worldwide.”

Thus the history of autism was written, paving the way for a decades-long attempt to cure, rather than adapt. Parents chased after any actionable advice they could find — some of it, unfortunately, looking legally actionable in retrospect (like shock therapy, for instance, and LSD). Even more important, because Kanner’s needle-­narrow definition of autism prevailed for so long, the public labored under the misapprehension that there was a sudden “epidemic” of autism when the DSM-III-R, published in 1987 (and just as critically, the DSM-IV in 1994), finally expanded the definition to include those who had slipped through the sieve for ­decades.