Emotions and individual differences shape foraging under threat

A common behaviour in natural environments is foraging for rewards. However, this is often in the presence of predators. Therefore, one of the most fundamental decisions for humans, as for other animals, is how to apportion time between reward-motivated pursuit behaviour and threat-motivated checking behaviour. To understand what affects how people strike this balance, we developed a novel ecologically inspired task and looked at both within-participant dynamics (moods) and between-participant individual differences (questionnaires about real-life behaviours) in two large internet samples (n=374 and n=702) in a cross-sectional design. For the within-participant dynamics, we found that people regulate task-evoked stress homeostatically by changing behaviour (increasing foraging and hiding). Individual differences, even in superficially related traits (apathy-anhedonia and anxiety-compulsive checking) reliably mapped onto unique behaviours. Worse task performance, due to maladaptive checking, was linked to gender (women checked excessively) and specific anxiety-related traits: somatic anxiety (reduced self-reported checking due to worry) and compulsivity (self-reported disorganized checking). While anhedonia decreased self-reported task engagement, apathy, strikingly, improved overall task performance by reducing excessive checking. In summary, we provide a novel multifaceted paradigm for assessment of checking for threat in a naturalistic task which is sensitive to both moods as they change throughout the task and clinical dimensions. Thus, it could serve as an objective measurement tool for future clinical studies interested in threat, vigilance or behaviour-emotion interactions in contexts requiring both reward-seeking and threat-avoidance.