Fear generalisation, a process by which conditioned fear spreads to similar but innocuous stimuli, is key in understanding why some individuals feel unsafe in objectively non-threatening situations. Both trait neuroticism and lack of predictability about the likelihood of feared consequences are associated with negative affect in the face of ambiguity and may increase the degree to which fear generalises. Undergraduates with varying degrees of neuroticism were randomised to either high- or low-instructional predictability conditions prior to fear acquisition. A fear generalisation (...) test measured risk ratings and attentional bias on a modified dot-probe paradigm. Among individuals with higher neuroticism, providing instructional predictability did not reduce fear; these individuals reported higher risk and increased attentional bias toward ambiguous stimuli. Overall, for individuals with higher neuroticism, predictability information hurt rather than helped interpretation of ambiguous stimuli, challenging a common conceptualisation of predictability as a factor that reduces fear. (shrink)