Prelinguistic evolution in early hominins: whence motherese?

Area of Science:

• Evolutionary biology
• Anthropology
• Linguistics

Background:

• Mother-infant interactions are crucial for understanding language evolution.
• Comparative studies of human and chimpanzee interactions offer insights into early hominin communication.
• Paleoanthropological evidence informs hypotheses about early hominin behavior and biology.

Purpose of the Study:

• To hypothesize the evolutionary origins of language by modeling early hominin mother-infant interactions.
• To explore the role of prosody and gesture in the development of protolanguage.
• To investigate the impact of increasing brain size and birth complications on maternal care strategies.

Main Methods:

• Comparative analysis of mother-infant gestural and vocal interactions in chimpanzees and humans.
• Modeling of early hominin interactions based on comparative data and paleoanthropological evidence.
• Integration of biological and behavioral data to formulate evolutionary hypotheses.

Main Results:

• Pre-linguistic vocalizations with motherese-like prosody likely evolved in response to increased birth difficulties in late australopithecines/early Homo.
• Hominin mothers may have adopted foraging strategies requiring them to silence, reassure, and control infants.
• Conventionalization of word meanings may have arisen from mothers using prosodic and gestural cues to guide infant behavior.

Conclusions:

• The evolution of language may be linked to adaptations in maternal care driven by biological and environmental pressures.
• Prosodic vocalizations and gestural communication were likely precursors to spoken language.
• Vigilant maternal attention and the capacity for conscious modification of vocalizations and gestures were key selective pressures.