Different Sources of Social Capital and Loneliness Among Adults in Shanghai, China: Exploring Sex Differences

Loneliness is a global health concern that negatively impacts physical/mental health. Social capital, encompassing resources from social networks, may protect against loneliness. We investigated the association between different sources of social capital and feelings of loneliness and examined whether these associations differ by sex. An online survey of 3220 Shanghai residents (mean age 34.5 years, 48.5% females) was conducted in 2022, Shanghai, China. We assessed bonding and bridging social capital using the revised 8-item Personal Social Capital Scale (PSCS) and used the revised three-item UCLA Loneliness Scale to measure loneliness. Multivariable linear regression analysis results suggest that both bonding (β coefficient: −0.152; SE: 0.035) and bridging social capital (β coefficient: −0.131; SE: 0.036) were significantly associated with lower loneliness, adjusting for sociodemographic characteristics, health conditions, and COVID-19-related factors. Notably, the mitigating effect of bonding social capital on loneliness was more pronounced in females, as indicated by significant interactions between sex and bonding social capital. Our study findings indicated that social capital serves as a protective factor against loneliness for Chinese adults, with bonding social capital having a stronger effect among females. Policies and interventions strengthening bonding social capital may facilitate reduced feelings of loneliness among Chinese, especially females.