Loneliness Across Borders: A Cross-Sectional Study of Young Adults in Germany and Japan

Abstract

Despite growing evidence that loneliness is a global public health concern, much of the existing research remains concentrated in specific cultural contexts, limiting our understanding of how loneliness manifests across societies. This research explores cross-cultural variations of loneliness and its relations with life satisfaction and health-related behaviors among young adults in Germany and Japan. In a cross-sectional online study with N = 920 participants (340 from Germany, 580 from Japan), aged 18–30 years, significant differences were observed between the two samples, with the Japanese group reporting lower loneliness scores, while the German group showed higher life satisfaction and health behavior scores. Contrary to expectations, results indicated that the negative association between loneliness and both life satisfaction and health-related behaviors was not significantly moderated by culture. Similar trends emerged regarding the sociodemographic groups that were more likely to report higher loneliness scores in both countries, suggesting shared risk factors for loneliness across cultures. These findings highlight the importance of cross-cultural studies in loneliness research, especially for diverse cultural contexts beyond Western populations.