Assessing the validity of three measures of loneliness through correlations and nomological networks

• Compared single item, three-item, and 20-item loneliness measures. • Measures had high correlations, suggesting convergent validity. • Profiles with personality, age, and sex were stronger for multi-item measures. Examining loneliness with self-reports can be done succinctly with a single item, briefly using a few items, or more extensively with longer scales. The present study examines three loneliness measures: a single item, a three-item scale, and a 20-item scale. Participants ( N = 407) completed the three measures of loneliness, a personality inventory measuring six dimensions, and provided demographic information of age and sex. With respect to convergent validity, there were high correlations (between 0.49 and 0.69) among the three loneliness measures. Intraclass correlations demonstrated stronger profile similarity with demographic variables and personality dimensions for the three-item and 20-item loneliness measures compared to the single item. We conclude that each loneliness measure does assess a similar construct but caution using the single item only because of unknown reliability in cross-sectional studies.