From natural to conventional word order: iconicity, simplicity and the mechanisms of linguistic evolution

所有的语言都有系统的结构，这使我们能够交流我们的思想。这种语言结构从何而来？语言的起源在于人类的思维方式，还是我们在语言中发现的结构是文化过程（如互动和学习）的结果？越来越多的人认识到，个人过程和文化过程在语言的进化中都起着作用，但它们是如何相互作用的还不清楚。我们将对这些语言进化的核心问题提供新的见解，通过进行一系列的实验室实验来观察视觉-手势模态（人工手语）中微型人工语言的出现，将我们的结果与自然发生的手语的数据进行比较，并将我们的研究扩展到另外两种模态：图形（使用图形图标）和声音（使用标志性声音）。在第一部分中，我们从即兴创作开始：当人们不能使用他们知道的语言时，他们如何传达信息？在实验中，参与者只使用身体而不使用语言来传达信息，我们发现他们不使用母语的词序。相反，顺序取决于所传达的意思。我们把这种依赖于意义的模式称为“自然秩序”：它代表了个体在为沟通问题即兴想出一次性解决方案时的偏好。真正的语言不是解决交流问题的一次性解决方案，而是在互动中使用的，并通过几代人的学习传承下来。我们将调查自然语序（即兴创作的结果）在被新个体学习并在互动中使用时发生了什么。自然的语序可能因意思而异，但语言通常在不同的意思之间系统地使用传统的语序。我们假设这是由于偏爱简单系统的学习偏见。因此，我们将进行人工手语学习实验，研究系统中的语序在学习后是否变得更加一致。此外，众所周知，当个体互动时，会发生结构启动：个体可能会重复刚刚在对话中出现的结构。在一个实现交际互动的即兴手势研究中，我们将研究词序变化如何受到启动的影响。这些实验将共同揭示学习和互动如何促进我们从即兴话语到语言系统的过程。进行实验室实验使我们能够在受控环境中详细研究学习和互动。然而，将实验室工作与自然主义背景下对同一现象的调查相结合，将拓宽我们研究结果的经验基础。在实验室中使用手势模态使我们能够在实验工作和现有手语研究之间建立一座桥梁。在项目的第二部分，我们将研究英国和德国手语的词序，以了解在大量人群中，长时间的学习和互动如何塑造对自然和简单的偏好。最后，在一系列创新实验中，我们将即兴手势与图形模态（参与者操纵标志性符号）和声音模态（参与者发出声音，而不是文字，以传达信息）进行比较。观察这些不同模式下的即兴表演将使我们能够测试我们之前手势实验结果的普遍性，并发现不同模式在象似性（形式和意义之间基于相似性的映射）方面的启示。总之，我们的多模态实验和手语研究将提供一种新的方式来看待创造结构化语言的机制。

All languages have systematic structure, which allows us to communicate our thoughts. Where does this linguistic structure come from? Do the origins lie in the way humans think, or are the structures we find in languages the result of cultural processes like interaction and learning? There is increasing recognition that both individual and cultural processes play a role in the evolution of language, but it is not clear how these interact. We will provide new insights into these central questions of language evolution by conducting a series of laboratory experiments looking at the emergence of miniature artificial languages in the visual-gestural modality (artificial sign languages), comparing our results to data from naturally occurring sign languages, and extending our investigation to two other modalities: the graphical (using graphical icons) and the vocal (using iconic sounds).In the first strand, we start from improvisation: how do people convey information when they cannot use the languages they know? In experiments where participants convey information using only their body and no speech, we have found that they do not use the word order of their native language. Instead the order depends on the meaning being conveyed. We call this meaning-dependent pattern 'natural order': it represents preferences in individuals when they improvise one-off solutions to communication problems. Real languages are not one-off solutions to communication problems but instead have been used in interaction, and transmitted through learning over many generations. We will investigate what happens to natural word order (the result of improvisation) when it is learned by new individuals, and used in interaction. Natural word order can vary from meaning to meaning, however languages typically use a conventional order systematically across meanings. We hypothesise that this is due to a learning bias favouring simple systems. Accordingly, we will conduct artificial sign language learning experiments, to investigate whether word order in a system becomes more consistent when it is learned. Moreover, it is known that when individuals interact, structural priming occurs: individuals are likely to repeat structures that have just occurred in conversation. In an improvised gesture study that implements communicative interaction, we will investigate how word order variability is affected by priming. These experiments together will uncover how learning and interaction contribute to the process that takes us from improvised utterances to a linguistic system. Conducting laboratory experiments allows us to study learning and interaction in detail in a controlled setting. However, pairing laboratory work with an investigation of the same phenomena in a naturalistic context would broaden the empirical basis of our findings. Using the gestural modality in the lab allows us to build a bridge between experimental work and the study of existing sign languages. In the second strand of the project we will examine word order in British and German Sign Language in order to see how preferences for naturalness and simplicity are shaped by learning and interaction, in large populations, over longer periods of time.Lastly, in a suite of innovative experiments, we will compare improvised gesture to the graphical modality (where participants manipulate iconic signs) and the vocal modality (where participants produce sounds, but not words, to convey information). Looking at improvisation in these different modalities will allow us to test the generality of our previous results from gesture experiments, and discover the affordances of different modalities with respect to iconicity (resemblance-based mappings between form and meaning). Together, our multi-modal experiments and sign language studies will provide a new way to look at the mechanisms that create structured languages.