Language Discrimination by Human Newborns and by Cotton-Top Tamarin Monkeys

TLDR

Humans uniquely use spoken language, yet it is unclear whether this ability depends on mechanisms unique to humans or shared with other species. The study examined whether newborn humans and cotton‑top tamarins can discriminate unfamiliar languages. Researchers employed a habituation‑dishabituation paradigm to test discrimination of Dutch and Japanese sentences versus their backward versions. Newborns and tamarins distinguished forward but not backward speech, suggesting that speech tuning relies on general primate auditory processes.

Abstract

Humans, but no other animal, make meaningful use of spoken language. What is unclear, however, is whether this capacity depends on a unique constellation of perceptual and neurobiological mechanisms or whether a subset of such mechanisms is shared with other organisms. To explore this problem, parallel experiments were conducted on human newborns and cotton-top tamarin monkeys to assess their ability to discriminate unfamiliar languages. A habituation-dishabituation procedure was used to show that human newborns and tamarins can discriminate sentences from Dutch and Japanese but not if the sentences are played backward. Moreover, the cues for discrimination are not present in backward speech. This suggests that the human newborns' tuning to certain properties of speech relies on general processes of the primate auditory system.