Highlights

・ Empirical evidence of the "inward-looking" trend: We empirically demonstrated the decline in extraversion among Japanese people using data. Previously, this was largely just a societal discourse.

・ A trend common to men and women: The decline in extraversion was observed in men and women, and the extent of change was similar between them.

・ A globally unique transformation: This trend is the exact opposite of the "increase in extraversion" reported in other countries (such as the United States, China, Germany, the Netherlands, and Sweden). This suggests that the decline in extraversion in Japan may be internationally unique.

Abstract of Press Release

Ryonosuke Akimoto, a graduate student at The University of Tokyo (who conducted this research at Aoyama Gakuin University), and Associate Professor Yuji Ogihara at Aoyama Gakuin University have revealed that the extraversion of Japanese people declined from 2010 to 2021 (Figure 1).

In Japanese media and social commentary, it has frequently been pointed out that Japanese people are becoming more "inward-looking." However, the extent to which it reflects an actual psychological shift in personality traits among the Japanese population has not been adequately examined. Therefore, an empirical examination was required.

Background

Extraversion is one of the Big Five personality traits, and it reflects people's activity and sociability. In Japanese media and social commentary, it has frequently been pointed out that Japanese people are becoming more "inward-looking (introverted: low in extraversion)." For example, the decrease in young people wishing to study abroad or work overseas is seen as a symbol of this trend. Industry leaders and policymakers have discussed this as a "national concern" (Yonezawa, 2014). However, sufficient empirical evidence regarding this "inward-looking" trend had not been obtained (Burgess, 2015; Kikuchi et al., 2015). By empirically analyzing longitudinal changes in extraversion, this study aims to offer new insights into the validity of the increase in inward-looking tendency in Japan.

Furthermore, previous studies conducted overseas have reported an increase in mean extraversion scores. This includes the United States (Twenge, 2001), China (Peng & Luo, 2021), the Netherlands (Smits et al., 2011), and Sweden (Billstedt et al., 2013). If a downward trend in extraversion is confirmed in Japan, it would contrast with the trends reported in other countries. Such a difference might help in examining the underlying causes of group-level changes in extraversion.

Therefore, in the present study, we comprehensively collected previous studies that measured the extraversion of Japanese people. By statistically analyzing the longitudinal changes in its mean values, we examined the reality of changes in Japanese personality. We also investigated whether there were any differences in the extent of this change based on gender or age.

Results

First, we investigated previous domestic studies that measured extraversion between 2018 and 2020. This was to determine the scale to be collected for our study. We found that the "Japanese version of the Ten Item Personality Inventory (TIPI-J; Oshio et al., 2012)" was the most frequently used scale in recent years. Therefore, we collected as many previous studies as possible that reported mean extraversion scores using this scale. The publication period was set from 2012 to 2022, because the TIPI-J was introduced by Oshio et al. (2012) in 2012, and studies published afterward were not yet widely available when we began our examination in August 2023. We then analyzed year-by-year changes while statistically controlling for attributes such as gender and age.

The analysis revealed that the extraversion of Japanese people has been declining in recent years, with both men and women showing a similar decline. Excluding the elderly group (for which sufficient data could not be collected), we also conducted separate analyses for "students only" and "adults only (20-60 years old)." A similar downward trend was observed in both age groups.

In addition, previous studies have shown that infectious disease outbreaks reduce people's extraversion (e.g., Mortensen et al., 2010). Therefore, we conducted an analysis limited to data up to 2019, excluding data from 2020 onward due to the COVID-19 pandemic. Even when the impact of the pandemic was excluded, a similar trend of declining extraversion was observed between 2010 and 2019. These results provide empirical backing for the discourse of the "inward-looking" trend among Japanese people.

This contrasts with the upward trends in extraversion reported internationally such as the United States (Twenge, 2001) and China (Peng & Luo, 2021), suggesting that the personality traits of Japanese people are transforming in a unique pattern.

A limitation of this study is that the analyzed period was restricted to 12 years, as the TIPI-J scale was first introduced in 2010. Further verification is necessary regarding changes over a longer-term span. In the future, we hope to clarify why this decline in extraversion is occurring. We also aim to multilaterally examine how this trend impacts other psychological traits and broader socio-economic indicators to better understand the cultural changes in Japan.

Billstedt, E., Waern, M., Duberstein, P., Marlow, T., Hellström, T., Ostling, S., & Skoog, I. (2013). Secular changes in personality: study on 75-year-olds examined in 1976-1977 and 2005-2006. International Journal of Geriatric Psychiatry, 28(3), 298–304. https://doi.org/10.1002/gps.3825

Burgess, C. (2015). To globalise or not to globalise? ‘Inward-looking youth’ as scapegoats for Japan’s failure to secure and cultivate ‘global human resources’. Globalisation, Societies and Education, 13(4), 487–507. https://doi.org/10.1080/14767724.2014.966805

Kikuchi, C, Sato, H, Shin, J & Tazaki, K. (2015). Are Japanese College Students Really Inward Looking?: A Comparative Study of Japan and Korea From the Viewpoint of Achievement Goals. Multicultural Relations, 12, 57–70. https://doi.org/10.20657/jsmrejournal.12.0_57

Mortensen, C. R., Becker, D. V., Ackerman, J. M., Neuberg, S. L., & Kenrick, D. T. (2010). Infection breeds reticence: the effects of disease salience on self-perceptions of personality and behavioral avoidance tendencies. Psychological science,21(3),440–447. https://doi.org/10.1177/0956797610361706

Oshio, A., Abe, S., & Cutrone, P. (2012). Development, reliability, and validity of the Japanese version of Ten Item Personality Inventory (TIPI-J). The Japanese Journal of Personality, 21(1), 40–52. https://doi.org/10.2132/personality.21.40

Peng, L., & Luo, S. (2021). Impact of social economic development on personality traits among Chinese college students: A cross-temporal meta-analysis, 2001–2016. Personality and Individual Differences, 171, 110461. https://doi.org/10.1016/j.paid.2020.110461

Smits, I. A., Dolan, C. V., Vorst, H. C., Wicherts, J. M., & Timmerman, M. E. (2011). Cohort differences in Big Five personality factors over a period of 25 years. Journal of Personality and Social Psychology, 100(6), 1124–1138. https://doi.org/10.1037/a0022874

Twenge, J. M. (2001). Birth cohort changes in extraversion: A cross-temporal meta analysis, 1966–1993. Personality and Individual Differences, 30(5), 735–748. https://doi.org/10.1016/S0191-8869(00)00066-0

Yonezawa, A. (2014). Japan’s challenge of fostering “global human resources”: Policy debates and practices.Japan Labor Review, 11(2), 37–52. http://www.jil.go.jp/english/JLR/documents/2014/JLR42_yonezawa.pdf

Publication Information

Title:　Decline of Extraversion in Japan: A Cross-Temporal Meta-Analysis
Journal:　Personality Science
Author:　Ryonosuke Akimoto, Yuji Ogihara
DOI:　10.1177/2700071026145252
Link:　https://doi.org/10.1177/27000710261452522
Publication date:　26th June, 2026

・ This article is open access and freely available to anyone. Tables and figures may be reused, provided that they are used in accordance with the appropriate guidelines.
・ The figure included in this press release may also be reused, provided that it is used in accordance with the appropriate guidelines.
・ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Contact

Research

Ryonosuke Akimoto (秋元 涼之介; First and corresponding author)
Master's Program
Department of Psychology, Graduate School of Humanities and Sociology
The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan.
Website: https://sites.google.com/g.ecc.u-tokyo.ac.jp/akimotoryonosuke/profile
Mail: 1889092375@g.ecc.u-tokyo.ac.jp

Ryonosuke Akimoto is a master's student at the Graduate School of Humanities and Sociology, The University of Tokyo. He began this research during his undergraduate studies at Aoyama Gakuin University. He then presented the findings at the 2025 Annual Convention of the Japanese Psychological Association—Japan's largest psychological conference—where he received the Excellent Presentation Award. His research interests include cultural shifts in Japan, extraversion, first impressions, face-based trait inferences, and their automatic processes.


Yuji Ogihara Ph.D. (荻原 祐二)
Associate Professor
Department of Psychology, College of Education, Psychology and Human Studies
Aoyama Gakuin University
4-4-25 Shibuya, Shibuya-ku, Tokyo, 150-8366, Japan
Website: https://sites.google.com/site/yujiogiharaweb/english
Mail: yogihara@ephs.aoyama.ac.jp

Yuji Ogihara, Ph.D., is an Associate Professor at the Department of Psychology, College of Education, Psychology and Human Studies at the Aoyama Gakuin University in Japan. He earned his doctorate from Kyoto University in 2015. His research interests include cultural change, interpersonal relationships, names, individualism, and culture. He has over 50 publications to his name. He is a recipient of numerous awards, including the 2024 Young Scientists’ Award (Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology, Japan), the 2022 Award for Distinguished Early and Middle Career Contributions (Japanese Psychological Association), and the 2015 Student Poster Award (Society for Personality and Social Psychology).

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