It is common to hear that older adults are very forgetful. Empirical research on age stereotyping maintains how awareness of age stereotypes lead older adults to experience social identity threat and underperform in cognitive tasks especially those related to memory. This study aimed to investigate the effectiveness of challenging the legitimacy of age stereotypes as an intervention to counter the negative impact of age stereotypes on cognitive performance in older adults. It was anticipated that self-categorising as older, in a test like situation, would lead older adults to underperform and that directly challenging the legitimacy of age stereotypes would help counter this performance decrement, especially in memory related tasks. Using a 2 X 2 between subjects design, healthy older adults ( N =60), aged fifty-five and above, were primed to self-categorise as older or younger and then either challenge or not challenge the legitimacy of the age stereotype of declining memory. Cognitive performance was then measured through a battery of standardised clinical tests assessing memory and language skills. As predicted, participants who self-categorised as younger and challenged the legitimacy of the age stereotype performed better. Notably, resistance by challenging was perceived in the older- challenge group who performed at par with the “younger” groups, with those self –categorised themselves as older and not challenging, performing the worst. Differences in performance were noticeable in tests of memory but not language. This empirical evidence of resisting underperformance in memory tests by challenging the stereotype has important clinical and social implications. For the applied field of diagnostic testing -as a potential intervention to avoid unnecessary costs resulting from misdiagnosis of medical conditions, like dementia. Overall, as a strategy, this could assist older adults resist the negative implications of aging and help them lead happier, well-adjusted lives.