One Lone Item: Assessing loneliness with a single-item direct measure

Across the most widely-used loneliness scales, the words ‘loneliness’ and ‘lonely’ are commonly avoided due to concerns about bias. These efforts, although made out of an abundance of caution, may have undermined scales’ abilities to assess loneliness accurately. In this article, we validate the One-item Loneliness scale (1iL; “I often feel lonely”), and show using multi-rater data (N = 352 people, recruited from Prolific) that it induces no more bias than popular indirect scales. The 1iL had retest reliability superior to some short multi-item scales (rtt = .74) and comparable cross-rater agreement (rCRA = .39). Using multi-rater adjustment, we find near-perfect convergence with the Three-Item Loneliness Scale (rtrue = .97), the most popular short measure of loneliness. We also find discriminant validity from a sister construct assessing social disconnection. Contrary to popular belief, loneliness is unidimensional, can be assessed directly, and is distinct from judgements about one’s social circle.