Chronological age is but one, and not the most accurate, indicator of human aging. Multiple outside (i.e., objective) and inside (i.e., subjective) perspectives on aging need to be considered to do justice to the multidimensionality of human development and aging. Outside perspectives are, for example, biological, social, and psychological ages. A chronological age of 75 years, for instance, may be linked with a different biological as well as cognitive age. Human development and aging is not only a biological process but is interactive in nature. As a result, it is characterized by impressive plasticity which entails the relativity of the meaning of chronological age. Outside perspectives are closely linked with inside perspectives on aging such as societal stereotypes, images about one's own old age and metastereotypes, that is, what we think others might think about old age. These inside perspectives, even though "invisible," are very powerful and exert effects on biological, social, and psychological ages alike and are affected by them. Future research needs to focus on furthering our understanding of the interactions taking place between biological, psychological, and sociocultural infl uences on the aging process and on the mechanisms linking personal, societal, and meta-images of old age.