Predicting others' knowledge in younger and older adulthood.

Our beliefs about aging affect how we interact with others. For example, people know that episodic memory declines with age, and as a result, older adults' memories are less likely to be trusted. However, not all aspects of remembering decline with age; semantic memory (knowledge) increases across adulthood and is relatively unaffected in healthy aging. In the current work, we examined people's awareness of this pattern. Participants estimated the knowledge of hypothetical younger and older adults; in some studies, they also predicted and demonstrated their own knowledge on the same measures. Across studies, both younger and older adults estimated that older adults would perform better on a knowledge test, demonstrating awareness that knowledge is not impaired with aging. Furthermore, people's beliefs about their own knowledge influenced the predictions they made about others' knowledge. We discuss how this work informs theories of metacognition and contributes to positive self-perceptions in older adulthood.