AbstractThe experiment was designed to study the effect of personal control, operationalized in terms of choice between a more demanding and a less demanding task, on persons with different levels of reactivity. Subjects were randomly assigned and individually tested in a 2 (High reactivity/Low reactivity) × 2 (Low rate of stimulus presentation/ High rate of stimulus presentation) × 2 (Choice/No Choice) factorial experiment with 15 subjects per condition. The two principal dependent measures were the total number of correct responses in a serial RT task and the post‐task levels of anxiety, anger, and curiosity. The major finding was that while the availability of control had a positive effect on both task performance and affect, its role was situation‐specific, i.e. limited to the difficult task. Most probably the availability of control masks the variability of reaction due to individual differences in reactivity. However, high‐reactives are still left with the residual stress of unresolved e