Life satisfaction, loneliness, and depressivity in consistently single young adults in Germany and the United Kingdom.

Young adults increasingly abstain from committed romantic relationships. However, psychological theories of singlehood are lacking, and it remains unclear who selects into remaining single throughout emerging adulthood and how consistent singles' well-being is affected over time. Here, we included 17,390 initially never partnered respondents from three panel studies from the United Kingdom and Germany providing 110,261 yearly observations from ages 16 to 29. First, we used survival analysis to predict who remained single. Young adults with lower well-being, male gender, higher education, and living alone or with parents stayed single longer. Second, we compared within-person age trajectories of life satisfaction, loneliness, and depressivity between consistent singles and eventually partnered respondents. Across emerging adulthood, consistent singles experienced comparatively stronger life satisfaction decreases and loneliness increases. Well-being deficits became more pronounced in the later 20s, when depressivity increases also diverged between groups. Evidence for moderation of these changes (e.g., by gender) was absent or inconsistent. Third, we examined how the first romantic relationship affected well-being aspects longitudinally. In both the short and long term, the first romantic relationship was associated with increases in life satisfaction and decreases in loneliness but not depressivity. Together, the findings indicate moderate average well-being risks when staying single in emerging adulthood. Well-being differences between consistent singles and eventually partnered respondents were minimal in adolescence but were exacerbated with prolonged singlehood. This highlights difficulties for first partnership formation in the later 20s because, concurrently, low well-being predicted remaining in singlehood longer. We discuss critical questions for singlehood theory development. (PsycInfo Database Record (c) 2026 APA, all rights reserved).