(SHORT VERSION) A simple way to disprove this hypothesis (the Innateness Hypothesis)
1. A simple way to disprove this hypothesis (the Innateness Hypothesis) is to demonstrate that other species have the capacity to speak but for some reason simply have not developed speech.
2. Perhaps they can acquire grammar like humans if they could only express it some other way.
3. It does not follow from their lack of speech, however, that chimpanzees are incapable of language.
4. Chimpanzees cannot speak because, unlike homo sapiens, their vocal cords are located higher in their throats and cannot be controlled as delicately as human vocal cords.
5. A logical candidate for such a species is the chimpanzee, which shares 98.4% of the human genetic code.