Development and evaluation of the reliability and validity of the Japanese Version of the Positive Solitude Scale.

Objectives Solitude is a state of being without social contact; it occurs when a person chooses not to interact with others, even when they are in the company of others. It is not necessarily accompanied by negative feelings. In contrast, loneliness, is a psychological state characterized by the feeling of needing the company of others. Most Japanese studies have regarded loneliness as an unpleasant and painful experience. In this study, focusing on solitude, we developed the Japanese version of the Positive Solitude Scale (JPSS) developed by Palgi et al. and evaluated its reliability and validity. This scale assesses the "conscious and voluntary decision to be alone as a positive experience."Methods A self-administered, anonymous questionnaire survey was conducted between May and August 2023, with 700 men and women participants aged 20 years or older living in Ward A, Sapporo. The survey items comprised basic attributes, the JPSS, subjective sense of health, subjective sense of well-being, and depression to verify convergent validity and social network and loneliness to verify discriminant validity. Additionally, principal component and correlation analyses were performed.Results A total of 245 questionnaires were collected, and 237 valid responses were obtained (valid response rate: 33.9%). The participants' mean age was 58.5±1.2 years and 111 (46.8%) were men; the Cronbach's alpha coefficient for the JPSS was 0.92. The principal component analysis revealed that all nine items had principal component loadings above 0.6, with a cumulative contribution of 62.3% to the overall scale. The total scale score was significantly positively correlated with subjective health (ρ=0.210, P=0.001), positive affect (ρ=0.302, P<0.001), and life satisfaction (ρ=0.241, P<0.001). There were no significant correlations among depression, negative affect, social networks, and loneliness.Conclusions The JPSS is a reliable and valid instrument unaffected by social networks and other social relationships. It is expected to be a promising new scale that can measure perceptions of time as a positive emotion, distinct from loneliness.