Nerd (adjective: nerdy) is a descriptive term, often used pejoratively, indicating a person that is overly intellectual, obsessive, or lacking social skills. Such a person may spend inordinate amounts of time on unpopular, little known, or non-mainstream activities, which are generally either highly technical, abstract, or relating to topics of fiction or fantasy, to the exclusion of more mainstream activities. Additionally, many so-called nerds are described as being shy, quirky, pedantic, and unattractive, and may have difficulty participating in, or even following, sports. Though originally derogatory, Nerd is a stereotypical term, but as with other pejoratives, it has been reclaimed and redefined by some as a term of pride and group identity.
People with autism, or its milder variant, Asperger's syndrome, are biologically disposed to have extreme S-brains. People described as nerds may stand squarely on the S-brain side of the spectrum, but not necessarily to such an extreme as to be diagnosed as Asperger's or autism. While not directly equatable with Asperger's, they have a lot in common.
The first documented appearance of the word nerd is as the name of a creature in Dr. Seuss's book If I Ran the Zoo (1950), in which the narrator Gerald McGrew claims that he would collect "a Nerkle, a Nerd, and a Seersucker too" for his imaginary zoo. The slang meaning of the term dates to the next year, 1951, when Newsweek magazine reported on its popular use as a synonym for or square in Detroit, Michigan. By the early 1960s, usage of the term had spread throughout the United States, and even as far as Scotland. At some point, the word took on connotations of bookishness and social ineptitude.