This essay reviews recent developments in longitudinal studies of aging, focusing on the Wisconsin Longitudinal Study (WLS) and the Health and Retirement Study (HRS). Both studies are part of an international movement to establish longitudinal biosocial surveys–in which biological measurement is joined with traditional survey techniques– and a related trend toward greater harmonization across studies. Both studies have collected DNA samples and are working toward genotyping that would facilitate broadly based studies of genetic and environmental effects on behavioral and health outcomes. The studies have each also focused on improved measurement of personality and of adaptive measures of cognitive ability. The HRS has expanded its economic measurements to longitudinal trajectories of consumption and to broader-based measurement of pension and Social Security wealth. It has added biomarkers of cardiovascular risk. The WLS has developed an integrated approach to the study of death and bereavement and an innovative use of high school yearbook photographs to capture information about health early in the lives of its participants. ABSTRACT FROM AUTHOR]; Copyright of EurAmerica is the property of EurAmerica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)