Jared Diamond and Bo Graslund agree on many aspects of the evolution of language while also holding contradictory ideas. Both theories center on Noam Chomsky’s linguistic theory of a built-in language program, or a mental grammar (Graslund, 107). As evidence of this inherent linguistic structure these authors offer the example of Creole languages. These languages have developed throughout the modern world progressing from a linguistic mix with limited functions to the fully functional Creole. Although Creoles occur throughout the world they tend to reinvent some grammatical features again and again suggesting a universal grammar (Diamond, 162).

Theories agree again when investigating the anatomical basis for spoken language. Quadrupeds such as apes cannot produce many human vocal sounds necessary for communication (Diamond, 55). However, numerous studies suggest their understanding of syntax, and an ability to understand spoken language; it is therefore the anatomy of their throats hindering them from speech (Graslund, 124). As humans progressed from Neanderthals to Cro-Magnons they developed Bipedalism. This upright position made space for the throat and palate to broaden in such a way that eventually made it possible to produce a greater variety of sounds (Graslund, 117). This increased capacity and finer control of sound lead to a greater inclination for innovation.

Graslund asserts that innovation and some sort of communication was occurring far before Diamond theorizes. Diamond asserts that Neanderthals died off  40,000 years ago and that Cro-Magnons appeared during the late ice age 4,000 years ago (Diamond 38).  These were the first peoples he asserts producing advanced tools indicating language and collaboration. Yet Graslund cites evidence of carefully crafter tools found from at least 400,000 years ago suggesting more advanced intelligence and planning capacity (Graslund, 113). Graslund also cites linguist Johanna Nichols’ investigation which suggests “… It would have taken about 100,000 years for the world’s current linguistic diversity to have developed from a single common language.” (Graslund, 109) This suggests a much earlier start to the beginning of language.