" The number of diagnoses of autism spectrum disorder almost certainly went up dramatically for another reason, one that hasn’t gotten as much attention as it should: a typographical error. Shocking but true. In the DSM-IV, the description of pervasive developmental disorder not otherwise specified that was supposed to appear in print was “a severe and pervasive impairment in social interaction and in verbal or nonverbal communication skills” (emphasis added). What actually appeared, however, was “a severe and pervasive impairment of reciprocal social interaction or verbal and nonverbal communication skills” (emphasis added). Instead of needing to meet both criteria to merit the diagnosis of PDD-NOS, a patient needed to meet either. "

― Temple Grandin , The Autistic Brain: Thinking Across the Spectrum