Toya Genta, Hashimoto Takashi
School of Knowledge Science, Japan Advanced Institute of Science and Technology, Nomi, Japan.
Front Psychol. 2018 Sep 19;9:1512. doi: 10.3389/fpsyg.2018.01512. eCollection 2018.
It has been suggested that hierarchically structured symbols, a remarkable feature of human language, are produced via the operation of recursive combination. Recursive combination is frequently observed in human behavior, not only in language but also in action sequences, mind-reading, technology, etc. in contrast, it is rarely observed in animals. Why is it that only humans use this operation? What is the adaptability of recursive combination? We aim (1) to identify the environmental feature(s) in which recursive combination is effective for survival and reproduction, and that has facilitated the evolution of this ability, and (2) to demonstrate the possible evolutionary processes of recursive combination. To achieve this, we constructed an evolutionary simulation of agents that generated products using recursive combination and used the results to explore the types of fitness functions (that reflect the kinds of adaptive environments) that give rise to this ability. We identified two types of adaptability of the recursive combination: (1) diversifiability of production and (2) diversifiability of products. Through the former, recursive combination promotes robustness against failure of production caused by inaccurate manipulations or irreversible changes. In an environment in which diversified products are preferable, sharing a portion of the production process for these products entails producing multiple products in which recursive combination plays a key role. We suppose that recursive combination works as a driving force of material culture. Finally, we discuss the possible evolutionary scenarios of recursive combination that is later generalized to encompass many aspects of human cognition, including human language.
有人提出，层次结构符号作为人类语言的一个显著特征，是通过递归组合操作产生的。递归组合在人类行为中经常被观察到，不仅在语言中，而且在动作序列、读心术、技术等方面。相比之下，在动物中很少观察到。为什么只有人类使用这种操作？递归组合的适应性是什么？我们的目标是：（1）确定递归组合在其中对生存和繁殖有效的环境特征，并且这种特征促进了这种能力的进化；（2）展示递归组合可能的进化过程。为了实现这一点，我们构建了一个智能体的进化模拟，这些智能体使用递归组合生成产物，并利用结果探索导致这种能力产生的适应度函数（反映适应性环境的类型）。我们确定了递归组合的两种适应性：（1）生产的多样性；（2）产物的多样性。通过前者，递归组合提高了对由不准确操作或不可逆变化导致的生产失败的鲁棒性。在一个多样化产物更受青睐的环境中，为这些产物共享一部分生产过程意味着生产多种递归组合起关键作用的产物。我们认为递归组合是物质文化的驱动力。最后，我们讨论了递归组合可能的进化情景，这种情景后来被推广到涵盖人类认知的许多方面，包括人类语言。
