Abstract
<p>Social isolation measures enforced during the COVID-19 pandemic highlighted the importance of the social environment in shaping affective states and decision-making. However, the day-to-day experience and psychological recovery from social deprivation, especially among individuals with high trait anxiety, remains poorly understood. We conducted a 10-day longitudinal study with 116 university students returning to campus, collecting ~31,000 momentary assessments of affect and social interactions during a three-day quarantine and subsequent period. Quarantine increased the need for social interaction and altered patterns of social engagement, whereas trait anxiety was robustly associated with reduced positive affect and elevated negative affect. Close interactions following quarantine were associated with higher positive affect. We also administered a virtual patch-foraging task to participants during and after quarantine. Greater variability in negative affect was associated with lower patch-exit thresholds, suggesting a tendency to persist in depleted patches. These findings highlight how trait anxiety shapes emotional experience and social behaviour in daily life and reveal how fluctuations in negative affect can influence sequential decision-making under uncertainty.</p>