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.
In this study, we comprehensively collected previous research that measured the extraversion of Japanese participants. We statistically controlled for attributes such as participants' age and gender, and analyzed the trends over a 12-year period.
As a result, it became clear that the extraversion of Japanese people has consistently declined in recent years. This downward trend occurred equally in both men and women, and the extent of change was similar between them. Furthermore, we conducted an analysis limited to data up to 2019 to account for the impact of the COVID-19 pandemic. This analysis also confirmed a similar decline. These findings provide empirical evidence for the long-standing discourse of an "inward-looking" trend among Japanese people.
The results of this research was published in the international academic journal Personality Science on June 26, 2026.
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.
