Development and Validation of a New Measurement Scale for Existential Loneliness.

This article deals with the development and initial validation of the Existential Loneliness Scale (ELS). An initial pool of 40 items, generated based on literature review, qualitative studies, and previously developed scales, was evaluated by the experts' judgment, so 30 items were retained and then administered to an Iranian sample of 433 youth and adult participants aged 20 to 85 years. Participants also completed other measures relevant for construct validity: Existential Loneliness Questionnaire (ELQ), De Jong Gierveld Loneliness Scale (DJGLS-6), Existential Anxiety Questionnaire (EAQ), Meaning in Life Questionnaire (MLQ), Beck Depression Inventory (BDI-13), and Satisfaction with Life Scale (SWLS). Exploratory factor analysis and parallel analysis showed strong evidence of unidimensionality. This result was also supported by confirmatory factor analysis test. Finally, 19 items were kept, which were free from DIF by gender and by marital status. The scale had high internal consistency (α = .95 and ω = .95) and adequate test-retest reliability with a 1-month interval (r = .74). Examination of the ELS' correlation with criterion measures indicated that the scale has good concurrent, discriminant, and convergent validity. Findings revealed the ELS as a reliable, valid, and suitable instrument to measure existential loneliness in the Iranian adult population.