Overall, emotional and social loneliness and their associated factors: a large-scale cross-sectional study of young and middle-aged adults in Germany

Technical Summary: Overall, Emotional, and Social Loneliness and Their Associated Factors in Young and Middle-Aged Adults in Germany

Problem Statement
Loneliness is increasingly recognized as a critical public health concern linked to adverse outcomes such as cardiovascular disease, depression, and premature mortality. However, existing empirical research predominantly treats loneliness as a unidimensional construct, focusing on "overall" loneliness. This approach obscures the distinct trajectories and associated factors of its two theoretically independent dimensions: emotional loneliness (arising from the absence of intimate, close relationships) and social loneliness (reflecting a perceived lack of broader social integration and group belonging). Furthermore, literature regarding young and middle adulthood (ages 18–51)—a life phase characterized by significant transitions in career, family, and mobility—remains scarce. While the COVID-19 pandemic has exacerbated these dynamics, there is a lack of large-scale, nationally representative data distinguishing between emotional and social loneliness in this specific demographic, particularly regarding how sociodemographic, social, health, and personality factors differentially impact these dimensions.

Methodology
This study utilizes a large-scale, nationally representative cross-sectional dataset from the German Family Demography Panel Study (FReDA). The analysis focuses on Wave 1B (autumn/winter 2021/22), supplemented by data from Wave 1A (depressed mood, partnership) and Wave 2B (personality traits).

• Sample: The final analytic sample comprised 14,443 adults aged 18 to 51 years. Respondents identifying as gender-diverse were excluded due to insufficient sample size for separate analysis.
• Measures:
  • Loneliness: Assessed using the validated De Jong Gierveld Loneliness Short Scale (DJGLS). The scale distinguishes between emotional loneliness (3 items) and social loneliness (3 items), with scores ranging from 0 to 3 for each dimension. Overall loneliness was calculated as the sum of both, rescaled to a 0–3 range for comparative analysis.
  • Predictors: Four sets of variables were analyzed: (1) Sociodemographics (age, gender, income, education, migration background, children); (2) Social Relationships (partnership status, social network discussion); (3) Health (mental health diagnoses, depressed mood, life satisfaction, physical conditions, obesity, pandemic burden); and (4) Personality (Big Five traits via BFI-2-XS).
• Analysis: Multivariable Ordinary Least Squares (OLS) regression models were employed. Variables were entered stepwise to assess the unique contribution of each set while controlling for others. Analyses were stratified by age and gender, and marginal means were calculated to illustrate trends. Robustness checks included multiple imputation for missing personality data.

Key Results

• Prevalence: High levels of loneliness were observed. 24.3% of participants reported intense emotional loneliness, 29.6% intense overall loneliness, and 35.9% intense social loneliness.
• Age-Related Patterns:
  • Overall Loneliness: Remained relatively stable across age groups (18–51).
  • Emotional Loneliness: Showed a decreasing trend with age, being highest in the 18–25 group and lowest in the 46–51 group.
  • Social Loneliness: Showed an increasing trend with age, being lowest in the 18–25 group and highest in the 46–51 group.
• Protective and Risk Factors:
  • Social Relationships: These showed the strongest protective associations. Having a partner and discussing personal matters within a social network were significantly associated with lower social loneliness.
  • Migration Background: First-generation migration was strongly associated with higher social and overall loneliness. Second-generation migration showed weaker, though still significant, associations.
  • Mental Health: Depressed mood and anxiety disorders were consistently associated with higher loneliness across all dimensions, with the strongest association observed for emotional loneliness.
  • Personality: Neuroticism was positively associated with all dimensions (strongest for emotional loneliness), while Agreeableness was negatively associated with social and overall loneliness.
  • Non-Significant Factors: Physical health conditions (e.g., diabetes, hypertension, obesity), educational attainment, and parental status (having children) were not significantly associated with any dimension of loneliness in this sample.
• Gender Differences: Gender differences were generally small. Females reported slightly higher emotional loneliness than males, particularly in the 31–40 age range, but no significant differences were found for overall or social loneliness.

Key Contributions

1. Multidimensional Differentiation: The study provides empirical evidence that emotional and social loneliness follow distinct, opposing age-related trajectories in young and middle adulthood, challenging the assumption of a single, stable loneliness curve.
2. Granular Factor Analysis: By separating the dimensions, the study reveals that risk and protective factors operate differently. For instance, social network ties and partnership status are most protective against social loneliness, whereas mental health burdens are most strongly linked to emotional loneliness.
3. Migration and Weak Ties: The findings support Granovetter's "strength of weak ties" theory, suggesting that first-generation migrants face specific deficits in social integration (weak ties) leading to higher social loneliness, rather than just a lack of intimate bonds.
4. Health Context: The study highlights that in young and middle adulthood, mental health and psychosocial factors are more salient correlates of loneliness than physical health conditions, which may become more relevant in later life stages.

Significance and Claims
The authors claim that this study advances the understanding of loneliness by demonstrating its multidimensional nature during a critical life stage often described as the "rush hour of life." The findings suggest that public health strategies and interventions cannot be "one-size-fits-all." Instead, effective prevention and care must be dimension-specific, tailored to the distinct mechanisms driving emotional versus social isolation.

The paper emphasizes that vulnerability to loneliness is not evenly distributed; individuals with mental health conditions, limited social networks, or a migration background are at higher risk. Consequently, the authors argue for the integration of loneliness screening and relational health promotion into routine healthcare. They caution that while the cross-sectional design limits causal inference, the large, representative sample provides a robust basis for identifying distinct patterns that challenge simplified age-based models of loneliness. The study concludes that addressing loneliness requires a nuanced approach that considers social context, relationship quality, and psychological resources alongside age.