WHAT PRESERVES THE EMERGENCE OF LANGUAGE? Anonymous authors Paper under double-blind review

Abstract

The emergence of language is a mystery. One dominant theory is that cooperation boosts language to emerge. However, as a means of giving out information, language seems not to be an evolutionarily stable strategy. To ensure the survival advantage of many competitors, animals are selfish in nature. From the perspective of Darwinian, if an individual can obtain a higher benefit by deceiving the other party, why not deceive? For those who are cheated, once bitten and twice shy, cooperation will no longer be a good option. As a result, motivation for communication, as well as the emergence of language would perish. Then, what preserves the emergence of language? We aim to answer this question in a brand new framework of agent community, reinforcement learning, and natural selection. Empirically, we reveal that lying indeed dispels cooperation. Even with individual resistance to lying behaviors, liars can easily defeat truth tellers and survive during natural selection. However, social resistance eventually constrains lying and makes the emergence of language possible.

1. INTRODUCTION

Unveiling the principles behind the emergence and evolution of language is attractive and appealing to all. It is believed that this research field is of great significance for promoting the development of enabling agents to evolve an efficient communication protocol (Nowak & Krakauer, 1999; Kottur et al., 2017; Chaabouni et al., 2019) or acquire existing one (Li & Bowling, 2019) , especially when interacting with humans. Previously, many studies have investigated some intriguing properties of language and their effects on the emergence of language (Andreas & Klein, 2017; Lazaridou et al., 2018; Mordatch & Abbeel, 2018) . The motivation behind these is that human language is considered as a remarkable degree of structure and complexity (Givon, 2013) and each character is the result of evolution, thus they believe that understanding the language itself is an indispensable step to take. Unlike existing work, we, from a different perspective, focus on a fundamental question that what made the emergence of language possible during evolution. One of the dominant theories in the community of emergent communication is: cooperation boosts language to emerge (Nowak & Krakauer, 1999; Cao et al., 2018) . Hence, there has been a surge of work investigating this field in cooperative multi-agent (mostly two agents) referential games (Lazaridou & Peysakhovich, 2017; Kottur et al., 2017; Das et al., 2017; Evtimova et al., 2018; Lazaridou et al., 2018) , a variant of the Lewis signaling game (David, 1969) . However, they seem to miss some basic elements in the human language. On one hand, human language emerges from the community, not just two persons, after all, language is learnable and can spread from one place to other (Dagan et al., 2020) . Studying a language in two-player games is like looking at the world through a keyhole. On the other hand, many works make an agreement that prior to the emergence of language some pre-adaptations occurred in the hominid lineage, and one of the candidates is the ability to use symbols (Deacon, 2003; Davidson, 2003; Christiansen & Kirby, 2003) . It seems understanding the emergence of symbolic signals is the key to approach the truth of the origin of language (Deacon, 1998) . However, chimpanzees have demonstrated a degree of language capacity by using arbitrary symbols as well as the ability for the cross-modal association, abstract thought, and displacement of thought in time (Meddin, 1979) . So why don't they have a language like us? One of the theory is selfishness has kept animal communication at a minimum (Ulbaek, 1998) . In more detail, if an individual can obtain a higher benefit by deceiving the other party in the cooperation, why not deceive? Once deception emerges, mistrust among individuals will haunt. For those who are cheated, once bitten and twice shy, cooperation will no longer be a good option. As a result,

