The Uniqueness of Language: A skeletal comparison of male human, chimpanzee, and gorilla skulls
The capability of speech is due largely to the anatomy of the human skull. The differences that are highlighted below are only a few of the anatomical differences that can be seen in these three primates. Other differences, such as the position of the hyoid bone in humans, the position of the vocal cords, and the developed Broca's area (a region in the brain), also aid in human's ability of speech.
The human skull: Small teeth, especially the canines, non-prognathic face, round cranium, speech conducive mandible, palate, and maxilla, prominent nose.
The chimpanzee skull: Large teeth, especially noticeable in the canines and incisors, prognathic face, long cranium, large browridges, nose is not prominent. The mandible, maxilla, and palate are not conductive to speech.
The gorilla skull: The largest of the three skulls, notice the massive canines and teeth, very prognathic mouth region, short and small cranium, massive mandible, large browridges and sagittal crest. The mandible, maxilla, and palate are not conductive to speech.
More information about the skeletal anatomy relating to language capabilities can be seen on our still photos pages of the hard palate and hyoid bone:
