In this study, we investigated the influence of negative emotions on numerosity estimation and whether this influence changes with aging during adulthood. Young and older adults were asked to estimate and compare the numerosity of collections of elements (cars or dots) with a two-digit number. Collections of elements were preceded by emotionally neutral (e.g., mushrooms) or emotionally negative (e.g., a corpse) pictures. Stimuli were easier (i.e., small-ratio) or harder (i.e., large-ratio) items. Young and older participants obtained similar numerosity estimation performance. Interestingly, participants were less accurate under negative emotions than under neutral emotions when they estimated numerosity of collections of abstract elements (i.e., dots). In contrast, participants improved their performance under negative emotions while estimating collections of non-abstract, daily-life elements (i.e., cars). These findings have important implications for furthering our understanding of the role of negative emotions in numerosity estimation and age-related differences therein.

We investigated the influence of negative emotions on arithmetic problem-solving performance and age-related differences therein. Participants were asked to verify complex multiplication problems that were either true (e.g., 4 × 26 = 104) or false (e.g., 5 × 41 = 201). Half the problems were five problems (e.g., 5 × 28 = 140) and half were non-five problems (e.g., 6 × 36 = 216). False five problems violated the five-rule, the parity-rule, both rules, or no rule. Problems were preceded by emotionally neutral or negative pictures. For true problems, emotions impaired performance while verifying non-five problems in young adults only and while verifying five problems in older adults only. For false five problems, negative emotions influenced young adults’ performance while verifying both-rule and no-rule violation problems but not when verifying parity-rule violation or five-rule violation problems. Negative emotions did not influence older adults’ performance whichever false five problems they solved. These findings suggest that negative emotions may change the mechanisms that participants use to solve arithmetic problems and that emotions influence young and older adults via different mechanisms.