| Abstract: | In agreement with Costa and McCrae (1992), the principle of ‘multiple uses’ of longitudinal studies is stressed based on a comparative review of the history of the Berkeley longitudinal studies and their different uses, and of those of the Bonn Longitudinal Study on Aging (BOLSA). Of the many uses of BOLSA, its contribution to the testing of a cognitive theory of aging is discussed. A selection of the findings of BOLSA and other studies of the Bonn Department of Psychology and the Institute of Gerontology, University of Heidelberg, is reported. These findings support three postulates of this theory: ( 1 ) the perceived rather than the objective situation directs behaviour; (2) perceptions of situations are related to dominant concerns of the person; and (3) adjustment to aging is achieved when a balance between the cognitive and motivational systems of the person has been attained. |
