White marmosets learn to speak through listening

Speech development in common marmosets similar to human speech development
Speech development in monkeys, contrary to previous assumptions, is very similar to human speech development. US scientists at Princeton University have shown in a recent study of white-eared monkeys (Callithrix jacchus) that they adapt their voice in interaction with their parents' sounds. So far, humans were the only primates that develop their voice partly by imitation of mother and father. In monkeys, science assumed that the changes in sounds are due solely to anatomical changes in the course of growth. With the current study, this decades-old conception of language acquisition in primates is now being tipped down, reports the research team around Daniel Takahashi of Princeton University in the journal "Science".

So far, human voice development has been considered unique in nature. It involves two parallel interactive processes, with the natural categories of sounds first changing as the vocal apparatus matures, and the children also being sensitized to certain characteristics of the sounds through verbal feedback and changing their sounds accordingly, Takahashi and colleagues explain. Our closest ancestor, the primates, has not been granted this ability, but their voice was considered independent of their parents' verbal feedback. However, this idea should be revised in light of the current study results.

Common marmosets develop their language depending on parental feedback. (Picture: Martina Berg)

Sound development of the monkeys can not be explained by growth alone
In the course of their investigations, the researchers observed the development of vocalisations in common marmosets from birth. They found that the sounds show "dramatic changes" that are "not just due to the simple consequences of growth."

Furthermore, experiments with parental interaction have shown that parental feedback significantly influences voice formation. Initially, the little monkeys alone are talking about squeaking noises, while the adult marmosets are more likely to whistle. Obtain the right Tonalgen the adolescent monkeys obviously about listening to their parents. So far, the assumptions on primate pronunciation are clearly refuted, according to Takahashi and colleagues. (Fp)