Gesture is the Primary Modality for Language Creation

How language began is one of the oldest questions in science, but theories remain speculative due to a lack of direct evidence. Here we report two experiments that generate empirical evidence to inform gesture-first and vocal-first theories of language origin; in each we tested modern humans’ ability to communicate a range of meanings (997 distinct words) using either gesture or non-linguistic vocalisation. Experiment 1 is a cross-cultural study, with signal Producers sampled from Australia (N=30, Mage=32.63, SD=12.42) and Vanuatu (N=30, Mage=32.40, SD=11.76). Experiment 2 is a cross-experiential study in which Producers were either sighted (N=10, Mage=39.60, SD=11.18) or severely vision-impaired (N=10, Mage=39.40, SD=10.37). A group of undergraduate student Interpreters guessed the meaning of the signals created by the Producers (N=140). Communication success was substantially higher in the gesture modality than the vocal modality (twice as high overall; 61.17% versus 29.04% success). This was true within cultures, across cultures and even for the signals produced by severely vision-impaired participants. The success of gesture is attributed in part to its greater universality (i.e., similarity in form across different Producers). Our results support the hypothesis that gesture is the primary modality for language creation.

语言起源之探究，乃科学史上久远之疑问，然由于缺乏直接证据，相关理论仍属推测性质。本研究报告两项实验，旨在生成实证证据，以增进对语言起源中手势先行与语音先行理论的了解；在每一实验中，我们测试了现代人运用手势或非语言性的声音表达一系列意义（997个不同词汇）的能力。实验一为一项跨文化研究，信号生产者来自澳大利亚（N=30，平均年龄32.63岁，标准差12.42）和瓦努阿图（N=30，平均年龄32.40岁，标准差11.76）。实验二为一项跨经验研究，其中生产者要么为视力正常（N=10，平均年龄39.60岁，标准差11.18）要么为严重视力受损（N=10，平均年龄39.40岁，标准差10.37）。一群本科生翻译者猜测生产者创造的信号的意义（N=140）。在手势方式中，沟通成功比率显著高于语音方式（总体成功率为两倍；61.17% 对 29.04%）。这一结果在文化内部、跨文化之间，以及对于严重视力受损参与者产生的信号中均成立。手势成功之处部分归因于其更大的普适性（即不同生产者之间形式的相似性）。我们的研究结果支持了手势是语言创造主要模态的假设。