that the paedomorphic (childlike) form of early hominin craniofacial morphology results from dissociation of growth trajectories.

Clark and Henneberg also argued that such shortening of the skull--which may have caused a descension of the larynx--as well as lordosis--allowing better movement of the larynx--increased vocal ability, significantly pushing back the origin of language to well before the evolution of Homo. They argued that self domestication was aided