BackgroundThe anchoring effect refers to the tendency that an individual’s numerical judgment would assimilate to an anchor (a numerical value) that appears before that judgment. This study investigated whether the anchoring effect exists in the emotion judgment of younger and older adults and observed the age-related characteristics. This could not only broaden the explanation of the anchoring effect but also link this classic judgment bias with daily emotion judgment to refresh our understanding of older adults’ ability in emotional perspective taking.MethodParticipants (older adults: n = 64, age range: 60–74, 27 males; younger adults: n = 68, age range: 18–34, 34 males) read a brief emotional story and compared the protagonist’s emotion intensity to a given numerical anchor (lower or higher than the anchor) and then estimated the protagonist’s possible emotion intensity in that story. The task was divided into two cases according to anchor relevance (anchors are relevant or irrelevant relative to the judgment target).ResultsThe results showed that the estimates were higher under high-anchor than low-anchor conditions, suggesting the robust anchoring effect. Further, the anchoring effect was greater for anchor-relevant than anchor-irrelevant tasks and for negative rather than positive emotions. No age differences were found.Discussion and conclusionsThe results indicated that the anchoring effect is robust and stable for younger and older adults, even though the anchor information seemed irrelevant. Finally, perceiving others’ negative emotions is a crucial but rather difficult aspect of empathy, which could be a challenge and requires more caution for accurate interpretation.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40359-023-01101-w.