Published online by Cambridge University Press: 14 February 2005
Motherese is a form of affective prosody injected automatically into speech during caregiving solicitude. Affective prosody is the aspect of language that conveys emotion by changes in tone, rhythm, and emphasis during speech. It is a neocortical function that allows graded, highly varied vocal emotional expression. Other mammals have only rigid, species-specific, limbic vocalizations. Thus, encephalization with corticalization is necessary for the evolution of progressively complex vocal emotional displays.
1. Personal communication from Janette Wallis, Ph.D., based on years of observing chimpanzees at Gombe Stream and other chimpanzee settings (wild and captive populations).