Evolinguistics is an attempt to clarify the origins and evolution of language and communication,thereby deepening our understanding of humans from an evolutionary perspective.The origins of language is characterized by the biological evolution of abilities related to language and communication,and the evolution of language by the structuralization and complexification of language knowledge as well as communication systems through cultural evolution.In Evolinguistics,two idiosyncrasies of human linguistic communication are the primary focus,namely,using hierarchically organized symbol sequences in language and sharing intentions in communication.We believe that the integration of these two characteristics made humans co-creative and smart,and in particular gave us knowledge co-creation capacity.The emergent constructive approach plays an important role in this research,which is a methodology to analyze complex systems by constructing and operating the evolutionary and emergent process of complex phenomena.Two studies taking this approach are introduced in this paper.One is a language evolution experiment in a laboratory to consider the process,mechanisms,and neural basis of symbolic communication systems.The other is an evolutionary simulation of recursive combination,which is thought of as the essential ability to form hierarchical structures.A hypothesis integrating intention sharing and recursive combination is discussed as an abductive reasoning mechanism for understanding others intentions.