This paper aims to situate language within ecological psychology and discuss its creativity from an ecological perspective. Based on the notion of ecological realism, which assumes that concrete and abstract relationships exist both equally and independently of agents in the human-environment sys tem, this paper claims the necessity of defining the two-phase process of actualizing and perceptualizing affordances. In the process, language is positioned as “perceptualizers” or “signifiers” in perceptualizing design. This new model of language enables further discussion of abstract concepts expressed by language and its creativity.

　Recent research on infant development investigates the impact of walking acquisition on the development of language and social behavior. Karen Adolph often refers to the relationship between motor development and a wide range of behavioral development as a developmental cascade, noting that motor development can instigate changes in perceptual, cognitive, and social development. This review is an overview of the literature by Adolph, who has been conducting studies on infant motor development, particularly focusing on walking, and examines the key words used in her studies, such as flexibility and experience, variability, and daily environment. Based on the suggestions from these studies, future research regarding an ecological approach to the development of locomotion is discussed.

　In this work, I take inspiration from classical developmental research, Thelen’s dynamic systems approach, and Japanese observational studies based on ecological psychology to suggest the perspective of viewing the development as continuous chronological changes in a system that encompasses both the body and its environment. I longitudinally observed N, an artisan who creates large one-ofa-kind works by Japanese woodturning, as she created two new works. I particularly focused on the main tools used in Japanese woodturning. My observations showed that N decided on the shape of each work in an exploratory manner, changed the fixture (“hame”) and processed it accordingly, and consistently changed and maintained the setup of tools in the workshop, such as changing the “kanna”handle. On the basis of these findings, I re-thought my theoretical considerations and came up with some new perspectives, such as the fact that development of craft can include not only physical development but also environmental changes such as changes in the setup of tools, and that the development of techniques can be viewed as an artist-tool system.