Parallels between sign stimuli and speech cues suggest some interesting speculations about the origins of language. Speech cues may belong to the class of human sign stimuli which, as in animal behavior, may be the product of an innate releasing mechanism. Prelinguistic speech for man may have functioned as a social-releaser system. Human language developed as a result of the intellect, which was capable of making a semantic representation of the world of experience and the phonetic social-releaser system. Linguistic capacity--the ability to learn the grammar of a language--was also necessary. Grammar evolved to interrelate the semantic product of the intellect and the phonetic product of the prelinguistic communication system. References are included. (Author/VM)