Research has shown that young adults treat older adults with less blame and more forgiveness when they commit a social transgression. This study sought to understand whether the stereotype of an assumed positive personality and/or a supposed lack of cognitive ability are potential driving forces behind the greater leniency that young adults display toward older transgressors. Seventy-five young adult participants were randomly assigned to one of five experimental conditions. Participants’ aging stereotypes were primed with one of four paragraphs that depicted older adults as (a) socially warm and cognitively competent, (b) socially cold but cognitively competent, (c) socially warm but cognitively incompetent, or (d) socially cold and cognitively incompetent. A fifth group of participants was assigned to a control condition in which aging stereotypes were not deliberately activated. Participants then read 16 vignettes that varied in terms of (1) the age of the transgressor, (2) how socially close the participant is to the transgressor, and (3) the severity of the transgression. After reading each individual vignette, participants indicated how much they blamed the transgressor for the outcome, and how likely they would be to forgive him or her despite the outcome. Relative to younger transgressors, older transgressors were blamed less, and had a higher likelihood of receiving forgiveness. Participants were also more likely to forgive and less likely to blame transgressors after having been primed with a stereotypical older adult who is socially warm but cognitively incompetent. Inconsistent with expectations, the effect was not unique to the rating of older adult transgressors; it also applied to young transgressors.