"When i feel lonely, i'm not nice (and neither are you)": the short- and long-term relation between loneliness and reports of social behaviour.

Loneliness can negatively impact peoples' lives. However, it is unclear whether loneliness influences, and is influenced by, people's social experience. Consistent with socio-cognitive models of loneliness, we hypothesised that loneliness predicts experienced social behaviour and vice versa. We tested these hypotheses in a sample of N = 245 college students (31.4% male) who participated in a two-year longitudinal survey. A subsample (n = 87, 24.1% male) also participated in a 14-day diary survey. This enabled us to test both long- and short-term associations between loneliness and social behaviour. Moreover, we investigated between-person (i.e. prolonged) and within-person (i.e. temporary) effects between loneliness and reports of social behaviour. Multilevel modelling showed that loneliness predicted individuals' reports of own and others' positive social behaviour, and reports of others' positive social behaviour predicted loneliness at the between-person level (while most of the effects at the within-person level were nonsignificant) in both the short and long term. The results suggest that people with higher levels of prolonged (but not temporary) loneliness tend to report less positive social behaviour, and people who experience others' behaviour less positively are more likely lonely. This study highlights the relation between prolonged loneliness and social behaviour.