Frustration Inversely Predicts Reactive Aggression: An Exploratory Multimodal Study Using Mouse Force Pressure in the PSAP-FS

Abstract

Reactive aggression is difficult to study in laboratory settings due to the lack of ecologically valid behavioural measures. Frustration, a key antecedent of aggression, remains underexplored as a quantifiable construct. This exploratory study tested whether mouse force pressure during clicks could serve as a proxy for frustration and whether frustration predicts reactive aggression using the Point Subtraction Aggression Paradigm - First Session (PSAP-FS). Thirty-three participants completed the task while mouse force, resting-state EEG (β-to-δ ratio and frontal α asymmetry), and trait aggression (BPAQ) were measured. Compared with before, mouse force increased after provocation during non-retaliatory behaviours, supporting its interpretation as a marker of frustration-related arousal. However, this increase was negatively associated with reactive aggression. Post-provocation mouse force was also linked to a decrease in β-to-δ ratio compared to pre-provocation, indicating heightened emotional reactivity relative to cortical control. Trait anger consistently predicted reactive aggression but was negatively associated with post-provocation force compared to pre-provocation, highlighting the differential role of trait anger in frustration and reactive aggression. Neither frontal α asymmetry nor other BPAQ subscales were significantly related to mouse force or reactive aggression. Overall, mouse force appears to index frustration-related arousal, which inversely predicts reactive aggression. These findings emphasise that although frustration and reactive aggression are related, they function as distinct processes. Future research should refine the use of mouse force as a behavioural metric and replicate these findings across larger, gender-balanced samples.