Acquisition of Hostile Expectation Biases in an online sample

Individuals with hostile expectations (HEX) anticipate harm from seemingly neutral or ambiguous stimuli. However, it is unclear how HEX are acquired, and whether specific components of HEX learning can predict antisocial thought, conduct, and personality. In an online sample of healthy young individuals (n=256, 69% women), we administered a virtual shooting task and applied computational modelling of behaviour to investigate HEX learning and its constellation of correlates. HEX acquisition was best explained by a hierarchical Bayesian model of reinforcement learning. Crucially, we found that individuals with relatively higher self-reported aggressiveness and psychopathy developed more pronounced and uncertain hostile beliefs as well as stronger prediction errors. Surprisingly, aggressive and psychopathic traits were further associated with more temporally stable hostility representations. Our study thus shows that aggressiveness and psychopathy are linked with the acquisition of robust yet sluggish and imprecise hostile beliefs.