Michael C. Corballis in American Scientist:
Throughout the world, and dating back to antiquity, deaf people have communicated with one another by means of sight rather than sound, using their hands and faces. Signed languages are still often regarded as vastly inferior to speech and are perceived as relying on mere mimicry or pantomime to convey meaning. And historically, the deaf have been treated as though they were mentally disabled. Spurred in part by the late, legendary William C. Stokoe of Gallaudet University, most linguists have now come to accept that sign languages have all of the grammatical and expressive sophistication of true language. Not all linguists have seen the light, though—as recently as late 2005, at the end of a talk in which I made reference to sign language, a prominent linguist stood up and informed the audience that sign language was a primitive pantomime invented in the 18th century and had no relevance to the understanding of true language or its evolution. The two books under review, Talking Hands and The Gestural Origin of Language, are powerful correctives to that antediluvian view.