Tadamasa Kimura

Born in Tokyo in 1964, Kimura began his career in cultural anthropology, training under Charles Frake and Leonard Talmy at the University at Buffalo, where he developed a foundation in cognitive anthropology and cognitive semantics. Since the early 1990s he has focused on the sociocultural dimensions of the internet and digital networks, becoming one of Japan's leading researchers in this field.

Before joining Rikkyo University in 2015, he served as a faculty member at Waseda University and at the University of Tokyo, where he was Head of the Department of Cultural Anthropology in the Graduate School of Arts and Sciences.

His current work centres on three projects: the Online Public Opinion Study (OPOS), which integrates Moral Foundations Theory (MFT) and evolutionary/cumulative cultural learning theories to analyse the formation and structure of online public opinion; the Log Data Analysis of Smartphone Use (LDASU), a large-scale log-data project conducted in collaboration with Fuller Inc.; and an ongoing theoretical programme developing the Truth-Default Ingroup Hypothesis (TDIH) as a framework for understanding online polarisation.

His 2012 book The Age of Digital Natives (Heibonsha Shinsho) became widely read in Japan and contributed to public debate on generational change and digital media. His 2018 monograph Hybrid Ethnography (Shin'yōsha) systematised his mixed-methods approach to computer-mediated communication research.

Two books appeared in 2026. Smartphones Manipulate the Mind (Asahi Shinsho) draws on the LDASU project's large-scale smartphone log data to examine how habitual device use shapes cognition, attention, and wellbeing — arguing that the architecture of smartphone interaction exerts a measurable influence on mental states that users rarely notice. The Structure of Net Public Opinion (Shin'yōsha) synthesises more than a decade of OPOS research, offering a comprehensive empirical and theoretical account of how online public opinion forms, polarises, and diverges from offline sentiment, with particular attention to the role of moral psychology and cumulative cultural learning.

He has been active in the Society of Socio-Informatics (SSI) since 2002, serving in multiple capacities including board member, chair of the planning committee, and member of the academic and editorial committees. He served as President of SSI from 2023 to 2025. He received the SSI Outstanding Publication Award in 2019 for Hybrid Ethnography.