Data from: Vocal turn-taking in a nonhuman primate is learned during ontogeny

Conversational turn-taking is an integral part of language development, as it reflects a confluence of social factors that mitigate communication. Humans coordinate the timing of speech based on the behaviour of another speaker, a behaviour that is learned during infancy. While adults in several primate species engage in vocal turn-taking, the degree to which similar learning processes underlie its development in these non-human species or are unique to language is not clear. We recorded the natural vocal interactions of common marmosets (Callithrix jacchus) occurring with both their sibling twins and parents over the first year of life and observed at least two parallels with language development. First, marmoset turn-taking is a learned vocal behaviour. Second, marmoset parents potentially played a direct role in guiding the development of turn-taking by providing feedback to their offspring when errors occurred during vocal interactions similarly to what has been observed in humans. Though species-differences are also evident, these findings suggest that similar learning mechanisms may be implemented in the ontogeny of vocal turn-taking across our Order, a finding that has important implications for our understanding of language evolution.

会话轮流发声（conversational turn-taking）是语言发展的不可或缺的组成部分，因其反映了共同作用以促进沟通的各类社会因素的汇聚。人类会依据对话伙伴的行为调整自身的说话时机，这一行为于婴儿期习得。尽管多个灵长类物种的成年个体均存在发声轮流行为，但目前尚不清楚，这类非人类物种的发声轮流行为的发展在多大程度上依赖类似的学习过程，亦或是该行为仅为语言所独有。本研究记录了普通狨猴（Callithrix jacchus）在出生后第一年，与其同胞双胞胎及父母之间的自然发声互动，并观察到其与人类语言发展至少存在两处相似之处。其一，狨猴的轮流发声行为属于后天习得的发声行为。其二，狨猴父母可能在引导轮流发声行为的发展中发挥了直接作用：当幼崽在发声互动中出现失误时，它们会向幼崽提供反馈，这与人类中观察到的现象一致。尽管物种间的差异同样显著，但上述研究结果表明，在灵长目类群的发声轮流行为的个体发育过程中，可能存在共通的学习机制。这一发现对于我们理解语言演化具有重要意义。