This dissertation focuses on examiner effects, defined as systematic variation in examinees’ responses and cognitive performance as a function of who conducts the evaluation. This work distinguishes between examiner characteristics and examiner behaviors (i.e., communicative and interactional actions), and conceptualizes examinee responses as cognitive, affective, and behavioral reactions. To account for these dynamics, the dissertation introduces the TRACE framework, which integrates mechanisms such as stereotypes, expectancy effects, stereotype threat, interactional processes, and prejudice pathways to explain how examiner-related factors influence performance. Using secondary data, the analyses identify a robust examiner-age effect: older adults perform better on recall, verbal fluency, and numeracy tasks when assessed by older rather than younger examiners. This effect emerges both within individuals over a nine-year period and across cohorts. While cross-national indicators of negative age stereotypes are associated with lower overall cognitive performance, they do not moderate examiner-age effects. Laboratory studies show examiner behavior is age-contingent and primarily shapes subjective evaluation experience rather than objective performance. Finally, although examiner prejudice and intergenerational contact are linked to cognitive impairment risk, they do not mediate examiner-age effects.