The extant literature has generally demonstrated that young adults can detect the trait aggression of another person with limited information. However, there is little research that investigates the life course persistence of aggression detection accuracy. Here, we aimed to explore the accuracy of older adults at detecting potential aggressors. Thirty-nine older adults (M = 71.49, SD = 7.59) and eighty-seven young adults (M = 20.24, SD = 1.74) made intimidation judgments, via video recordings, for nine people (targets). ‘Aggression detection accuracy’ was shown in the relationship between the intimidation judgments made by participants and the targets’ responses to the Buss-Perry Aggression Questionnaire. Both age groups were highly accurate in their recognition of trait aggression and accuracy was maintained into older age, with no difference in accuracy between the older and young adults. There was, however, more variability in the ratings given by the older adults compared to the young adults, suggesting less consensus in judgment for the older compared to the young group. Overall, the participants in this study were highly accurate at detecting trait aggression. There was no difference in average aggression detection between older and young adults but there was in sample agreement. These results are discussed in the context of age effects on intimidation, as well as research in accurate aggression detection.